Laminar How Control (1976- 1982)

NASA T" 84496 NASATechnical Memomdm 844% c.1

Laminar How Control (1976-1982) A Selected, Annotated Bibliography

Marie H. Tuttle and Dal V. Maddalon

AUGUST 1982

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NASA NASATechnical Memorandm -%

Laminar flow Control (1976-1982) A Selected, Annotated Bibliography

Marie H. Tuttle and Dal V. Maddalon Langley Research Center Hampton, Virginia

National Aeronautics and Space Administration Scientlflc and Technlcal Information Branch \. i ” INTRODUCTION ...... 1

BIBLIOGRAPHY (1976-1982) ...... 3

APPENDIX ...... 65

ENTRIES WITH PUBLICATIONDATES PRIOR TO 1976 ...... 66

AUTHOR INDEX ...... 76

iii INTRODUCTION

The purpose of thisselected bibliography is to list available,unclassified laminarflow research completed since the ACEE/LFC Program was begun. This bibliography is therefore limited to researchconducted from about 1975 to mid 1982.

The reports listed hereinemphasize the aerodynamics and systems studies which were the main product of this work, but some structuresreports are also included. Aerodynamic research is mainly limited tothe subsonic and transonicspeed regimes. Becausewind-tunnel flow qualities such as free stream disturbancelevel play such an important role in boundary-layertransition, much researchhas recently been done in this area and it is also included.

Laminarflow controlresearch through 1978 was extensivelysurveyed in NASA RP-1035 (citation 141). Some pertinentpublications from thatreference are also includedhere. In addition, there is available a bibliography(citation 7) of Air ForceFlight Dynamics Laboratory (AFFDL) reports on LFC whichsummarizes work accomplishedduring the X-21 program. A third LFC bibliography(citation 25) has been published by Lockheed-Georgia.

The appendixof this compilation includes reports published prior to 1976 which were not included in NASA "1035 but are pertinent to this subject.

Considerable effort was made to survey as mch relevant literature as possible from many differentsources. However, some importantpapers may havebeen inadvertentlyoverlooked.

Personswishing more information on specific topics shouldcheck the reference lists in those documentsdescribed herein which are pertinent to their interest. They also are urged to use the services available from NASA for computerdata bank searches.Technical libraries at NASA researchcenters can fill such requests.

The items selected for inclusion in this bibliography are generallyarranged chronologically by date of publication.Conference papers, however, are placed accordingto date of presentation. An authorindex is included at the endof the bibliography. In most cases, abstracts used are from the NASA announcement bulletins "Scientificand Technical Aerospace Reports" (STAR) and"International Aerospace Abstracts" (IAA). Inother cases, authors' abstracts were used. License was taken to modify or shorten abstracts. If it is known that a paper hasappeared in several forms,mention is made of this fact.

Identifyinginformation, including accession and report numbers(when known), is included in the citations in order to facilitate the filling of requests for specific items. When requesting material fromyour library orother Source, it is advisable to includethe complete citation;the abstract may be omitted.

A 11#11 after an accession number indicates that the document is also available in microfiche form.

Availability sources of thedieferent types of materials are given below:

Accession Number Type of Material Where Obtained

Axx-xxxxx Publishedliterature American Institute ofAeronautics in journals or andAstronautics Example: conferences, etc., TechnicalInformation Service A75-25583 as indicated. 555 West 57th Street, 12thFloor New York, NY 10019

AIAA-82-0567 AI- Papers

NXX-XXXXX ReportTechnical Nationalliterature unlessanother source InformationService (NTIS) Example: is given in the 5285 Port Royal Road N67-37604 citation Springfield, VA 22 16 1 xxx-xxxxx Reportliterature having NASA Scientific and some type of limited TechnicalInformation Example: distribution. Facility(STIF) X72-76040 P.O. Box 8757 B.W.I. Airport, MD 21240

Theses may beordered by Order Number from University Microfilms A Xerox Company 300 North Zeeb Road Ann Arbor, Michigan 48106

Any others - Ask yourlibrary, or NASA Scientific and Technical include any InformationFacility (STIF) information P.O. Box 8757 given B.W.I. Airport, MD 21240

2 BIBLIOGRAPHY

1. Aircraft Fuel ConservationTechnology. transport. The feasibility of hydrogen-fueled *Task forcereport. NASA TU-X-74295, Sept.9, aircraft is discussed. 1975, 141 pp. *StanfordUniv., Stanford, Calif. N77- 11055#

An advancedtechnology program is described 4. *Zuda, E.: Installation ofa Flow Straightener forreduced fuel consumption in air transport. inthe Subsonic Wind Tunnel. DFVLR-Nachrichten, Costbenefits and estimates are givenfor improved NOV. 1975, pp.697, 698. (In German. 1 enginedesign and components, turboprop propulsion systems,active control system, laminar flow A76- 13407 control, andcomposite primary structures. Turbulence-produceddisturbances in wind *NASA, Washington, D.C. tunnelexperiments led to the installation of a flow-straighteningdevice. The eliminationof turbulenceeffects in such a device is obtained by 2. *Canu, M.: Noiseand Turbulence in Transonic dividingthe area of theflow cross section into a Wind Tunnels.Report No. AAAF-NF76- 12; number of separatechannels. The use of cylindri- ISBN-2-7170-0390-8; Paris Assoc. Aeron. et caltubes for this purpose has certain disadvan- Astronautiquede France. Presented atthe 12th tages. It was, therefore,decided to employ EcoleNatl. Super. de Mecan. et d'Aerotech./CEAT regularhexagonal pipes for the design of theflow Colloq.d'Aerodyn. Appl., Poitiers,France, straightener. Aluminum pipes were selected 5-7Nov. 1975, 21 pp. (InFrench.) because of their low weight.Details concerning thedesign and theinstallation of thedevice are N77- 10082# discussed.

Reduction of noisein transonic wind tunnels, *DeutscheForschungs- und Versuchsanstaltfuer due largelyto wall perforations, was studied. Luft- und Raumfahrt. Zentralabteilung Different types of perforations were tested. Niedergeschwindigkeits-Windkanaeale, Porz-Wahn, Several of thesebring the noise level down to West Germany. that of guidevanes. The measurements were made withmicrophones or with hot wire probes;from the analogy of thespectra obtained it was concluded 5. *Bauer,Frances; *Garabedian, Paul; *Korn, thatnoise is themajor componentof the David;*Jameson, Antony; fBeckmann, M., ed.; turbulence. andfKuenzi, H. P., ed.: Supercritical Wing Sections 2, Volume 108. NASA CR-142229, 1975, +OfficeNational d' Etudes et deRecherches 301 pp. Springer-Verlag, 1975. Aerospatiales (ONERA), Modane, France N75- 18167

3. *Shevell, R. S.: Advanced SubsonicAircraft - A mathematicaltheory for the design and The TechnologicalResponse toFuture Air Trans- analysis of supercritical wing sections was previ- portation Needs. In:Princeton Univ. Conference ouslypresented. Examplesand computer programs Proceedings(A76-457761, Princeton, N-J., NOV- 10, showing how this method workswere included. The 11,1975, pp. 5-1 to 5-26. workon transonics is presentedin a more definitive form.For design, a better model of A76-45781# the trailing edge is introduced whichshould eliminate a loss of fifteenor twenty percent in Improvements,such as automaticflight mn- lift experiencedwith previous heavily aft loaded agement,advanced aerodynamics, laminar flow con- models, which is attributedto boundarylayer trol, advancedengines, and advanced structural separation. How dragcreep can be reduced atoff- materials, couldlead to significant reductions in designconditions is indicated. A rotatedfinite fuelrequirements; the development of new tech- difference scheme is presentedthat enables the nologies is, however,dependent on the economic application of Murman'smethod of analysisin health of theaviation industry. The historyof more or less arbitrarycurvilinear coordinate transport aircraft is reviewedas are technolog- systems. This allows the use of supersonic as icaladvances - dragreduction, weight reduction, well assubsonic free stream Mach numbers and to improvement inlift coefficient, etc. Some devel- capture shock waves as far back on an airfoil as opments in air transportation which raisedgreat desired.Moreover, it leads to an effectivethree expectations,but have failed to have a signifi- dimensionalprogram for the computation of tran- cantimpact are reviewed: laminar flow control, sonicflow past an oblique wing. In thecase of nuclear powered aircraft, STOL andthe supersonic two dimensionalflow, the method is extendedto takeinto account the displacement thickness com-

3 putedby a semi-empiricalturbulent boundary layer societyConference on hansportation, -.s Angeles, correction. Calif., July 18-23, 1976, 11 pp.

N76-20124b *New York Univ., New York. A77- 2945 1X

Contract AT( 11- 11-3077 Changes infuture aircraft technology which Grants NGR-33-016-201 and NGR-33-016-167 conserveenergy are studied,along with the effect ofthese changes oneconomic performance. Among the new technologiesconsidered are laminar-flow 6. fPovinelli, F. P.; *Klineberg, J. M.; and control, composite materials withand without *Kramer, J. J.: Improving Aircraft hergy laminar-flowcontrol, and advanced airfoils. Efficiency.Astronautics and Aeronautics, Aircraftdesign features studied include high- Vol. 14,Feb. 1976, pp. 18-31. aspect-ratiowings, thickness ratio, andrange. Enginetechnology is heldconstant at the JT9D A76- 19593# level. It is concludedthat wing aspect ratios of future aircraft are likely to significantly Investigationsconducted by a NASA task force increase as a result of new technologyand the concerningthe development of aeronauticalfuel- push of higherfuel prices. Composite materials conservationtechnology are considered. The task may raise aspect ratio to about 11 to 12 and forceestimated the fuel savings potential, pros- practical laminarflow-control systems may further pectsfor 'implementation in the civil air- increase aspect ratio to 14 or more. Advanced transportfleet, and the impact of thetechnology technologyprovides significant reductions in on air-transportfuel use. Propulsion advances aircrafttake-off gross weight,energy con- are related to existingengines in the fleet, to sumption,and directoperating cost. new production of currentengine types, and to new enginedesigns. Studies aimed at theevolutionary *NASA, LangleyResearch Center, Hampton, Va. improvementof aerodynamic design and a laminar flowcontrol program are discussedand possibili- ties concerningthe use of composite structural 9.*Payne, H. E.: Laminar Flow Rethink - Using materials are examined. CompositeStructure. Society of Automotive Engineers,Business Aircraft Meeting, Wichita, *NASA, Officeof Aeronautics and Space Technology, Kansas, April 6-9,1976, 12 pp. Aircraft EnergyEfficiency Office, Washington, D.C. SAE-76-0473 A76-31966

The useof composite structurein the design 7. *Jobe, Charles E. : A Biblioqraphyof ofthe Skyrocket 11, a generalaviation aircraft AFFDL/FXM Reports on Laminar Flow Control. capableof operating in the laminar flow "drag AFFDL-I"76-26-FXM, U.S. Air Force, Mar. 1976, bucket"on a normal service, is discussed. The 24 PP- aircraftdesign utilizes a verystiff epoxy/ fiberglasscomposite air-passage skin consisting N79-70034 ofrelatively few parts to eliminate air load stress ripples. A zero-liftdrag coefficient in AFFDL/FXM was the Air Forceoffice responsi- thearea of 0.15 hasbeen obtained by designengi- blefor technically monitoring the X-21A Laminar neeringspecifically for low drag,maximizing the Flow ControlFlight Demonstration Program and the extent of laminarflow by useof the stiff com- many associatedresearch contracts. Approximately positeskin, andminimizing protuberances into the 165 reports and technicalnotes remain from the air passage. LFC research, due to the critical shortage of file cabinetsand many "fileField days ." The biblio- *BellancaAircraft Engineering, Inc., Scott Depot, graphy is arrangedalphabetically by personal W. Va. authorand date. The corporateauthor was used when thepersonal author was unknown. The many progressreports are listed as such, by contract 10.%winford, G. R.: A PreliminaryDesign Study number. A cross-reference list by NORTHROP of a Laminar Flow Control Wing ofComposite BLC- ( ) number is contained onpage 22. Materials for Long Range TransportAircraft, Final Rept.,April. 1975 - Mar. 1976. NASA CR-144950, *AirForce Flight Dynamics Lab.,Wright-Patterson April 1976,125 pp. AFB, Ohio. N76-25146#

8. *Maddalon, D. V.; and *Wagner, R. D.: Energy The resultsof an aircraft preliminary design and Economic Trade Of fs for Advanced Technology study are reported. The selectedstudy airplane SubsonicAircraft. NASA TM-X-72833, April 1976, configuration is defined. The suctionsurface, 25pp. Also presented at the4th Annual Inter- ducting,and compressor systems are described. Techniquesof manufacturing suction surfaces are identified anddiscussed. A wingbox of graphite/ epoxycomposite is defined.Leading and trailing

4 A oflong-range passenger and cargo aircraft. The 5 edgestructures ofcomposite construction are firsttechnology centers around the use of a span- - described.Control surfaces, engine installation, loadedcargo aircraft with the payload distributed andlanding gear are illustrated and discussed. alongthe wing. The secondtechnology is the The preliminary wing design is appraisedfrom the application of laminarflow control to the air- standpoint ofmanufacturing, weight, operations, craftto reduce the aerodynamicdrag. The useof and durability. It is concludedthat a practical LFC canreduce the fuel requirements during long- laminarflow control (LFC) wingof composite range cruise. The last programevaluates the materialcan be built, and thatsuch a wing will production of alternate aircraft fuels from coal belighter than an equivalent metal wing. a As and theuse of liquid hydrogen as an aircraft result, a programof suctionsurface evaluation fuel andother studies of configuration,aerodynamics, . structuraldesign andmanufacturing, and suction *NASA, LangleyResearch Center, Hampton, Va. systemsare recommended. It is concludedthat future developmentof composite primary structure shouldconsider the requirements of LFC wings,and 13. Geddes, Pa: CivilTransport Technology up be coordinatedwith an LFC developmentprogram. J. to 2000- (NASA believesfuel consumption is the *BoeingCommercial Airplane Co., Seattle, Wash. major consideration.)Interavia, Vol.31, May Contract NASI- 13872 1976,pp. 419-421. A76-32649 11. *Denning, R. M.; *Miller, S. C.; and Wright, The recommendatlonsof a NASA task force G. H.: FutureTrends in Aero Gas TurbineDesign. formed to establish goals in a comprehensivepro- I1 Unconventionalhgines. Presented at the - ~~~ ~ ~ gram fordeveloping fuel conservation technology Royal AeronauticalSociety Spring Convention on forthe civil air transport industry are compared "Seedsfor Success in Civil Aircraft Design in the withtypical industry views of thedevelopments Next Two Decades," London, mgland, May 19, 20, thatare feasible in the near future. A +year 1976. AeronauticalJournal, Vol. 80,Sept. 1976, researchprogram for an advanced turboprop engine pp. 385-393. cruising at Mach 0.8 at 9,500 m hasbeen sug- A77- 11595 gested,together with improved engine components forexisting engines such as the JTBD,JTBD, and Unconventionaltypes of aircraft gas turbine CF6, includingmechanical mixers to mix thecore andduct stream beforedischarge through a common (GT) enginesreviewed are so treated in the sense of:unconventional uses (other than propulsion) nozzle,clearance control to improvecompressor forthe GT engine,modification of the thermo- andturbine efficiency, andimproved blade shapes. Four possibleaerodynamic approaches to fuel con- dynamic cycleunder some flightconditions, or use ofextremes of theconstant-pressure GT cycle. sumption were selectedfor future study: drag clean-up,improved aerodynamic design, laminar Variant thermodynamic/aerodynamic cyclesunder considerationinclude: a heat-exchangerengine, flowcontrol, and the use of small vertical end- propulsionsystems with ingestion or re-energizing plates on wing-tipsto augment thrust. work in of wake or boundary layerto reduce drag, and theseareas would be dividedbetween an Ehergy systemsresorting to laminar flow control or EfficientTransport program and a separate Laminar boundarylayer suction. Engines featuring in- Flow Controlprogram. A greatlyaccelerated flightvariation of the thermodynamiccycle effortin the development of compositestructures include:those using variable turbine stators, is urged. The totalcost of theproposed programs SSP variable-cycleengines with compressor switch- is $670 million; a fuelsavings of 79% over a ingvalve system, and variable-pitch fan engines. fleetincorporating current advanced technology is Enginesdeveloping vertical lift in addition to predictedfor a fleet resulting from thesuggested propulsivethrust include: blow-fanengines, program in the year 2005. externally blown flapengines, and rotatable remotelift/propulsion fan engines. 14. *Sturgeon, R. F.; *Bennett, J. A.; *Etchberqer,~. *Aero. Div.,Rolls-Royce ( 19711,Ltd., Bristol, F. R.; *Ferrill, R. S.; and *Meade, L. E.: Study

England of ~ the Application of Advanced Technologies to Lag.nar-FloLCntrol Systems forSubsonic hans- ports. Volume I: Summary. Finalwpt . NASA CR- 12. *Schrader, 0. E.: Application of Advanced 144975, May 1976,63 pp. Technology to Future Long-Range Aircraft.Pre- sented at theSociety of AlliedWeight mgineers, N76-24144# 35th Annual Conference,Philadelphia, May 24-26, 1976. NASA 'IM-X-73921, May 24,1976, 49 pp. A study was conductedto evaluate the technical andeconomic feasibility of applyinglaminar SAWE Paper 1126 A77- 12194) flowcontrol to the wingsand empennageof long- N76-29216# rangesubsonic transport aircraft compatible with initialoperation in 1985.For a designmission An assessment is presented of threeseparate range of 10,186 km (5500 n. mi. ), advancedtech- programs at LangleyResearch Center that have nologylaminar-flow-control (LFC) and turbulent- incorporatedadvanced technology into the design flow(TF) aircraft were developedfor both 200-

5 and400-passenger payloads, and compared on the Congress, 2nd Sess. 17 Feb. 1976, 28 pp.Avail- basis of productioncosts, direct operatingcosts, lable from U.S. Capitol,Senate Document Room.) and fuelefficiency. As part of thestudy, para- metricanalyses were conducted to establish the N77-17032# optimum geometryfor LFC and TF aircraft, advanced LFC systemconcepts and arrangements were evalu- A technologyplan is describedfor developing ated, and configurationvariations maximizing the fuel-efficientaircraft. Inputs were obtained effectivenessof LFC were developed.For the from industry, NASA researchcenters, and other final LFC aircraft,analyses were conducted to governmentalagencies. Six major programsare definemaintenance costs and procedures, manu- defined:engine componentimprovement, composite facturingcosts andprocedures, and operational primarystructures, turboprops, laminar flow con- considerationspeculiar to LFC aircraft. Compared trol, fuelconservative transport, and thefuel tothe corresponding advanced technology TF trans- conservativeengine. Funding requirements and ports,the 200- and400-passenger LFC aircraft benefits are discussed. realizedreductions in fuel consumption up to 28.2%, reductionsin direct operating costs up to 8.4%,and improvements infuel efficiency, in 18. *Maddalon, D. V.; andWagner, R. D.: Energy ssm/lb of fuel, up to 39.4%. Compared tocurrent and Economic Trade Of fs for Advanced Technology commercialtransports at the design range, the LFC SubsonicAircraft. In: Annual Intersociety Con- studyaircraft demonstrate improvements in fuel ference on Transportation,4th, Los Angeles, efficiency up to 131%.Research and technology Calif.,July 18-23, 1976,Proceedings (A77-29451) requirementsrequisite to thedevelopment of LFC ASME, 1976, 11 pp. transport aircraft were identified. A77- 2947 1 *Lockheed-Georgia Co., Marietta,Georgia. Contract NASI-13694 Changes infuture aircraft technology which conserveenergy are studied, along with the effect of thesechanges on economicperformance. Among 15. *Sturgeon, R. F. ; *Bennett , J. A. ; the new technologies considered are laminar-f low *Etchberger, F. R.; *Ferrill, R. S.; and *Meade, control,composite materials with and without L. E.: Study of theApplication of Advanced laminar-flowcontrol, and advanced airfoils. Technologiesto Laminar-Flow ControlSystems for Aircraftdesign features studied include high- SubsonicTransports. Volume 11, Analyses. NASA aspect-ratiowings, thickness ratio, andrange. CR-144949, May 1976, 471 pp. Enginetechnology is heldconstant at the JT9D level. It is concludedthat wing aspect ratios of N76-24145# futureaircraft are likely to significantly increaseas a result of new technologyand the The abstractgiven in Volume I coversboth pushof higher fuel prices. Whereas currentair- volumes. planeshave been designed for AR = 7,super- criticaltechnology and much higherfuel prices *Lockheed-Georgia Co., Marietta, Ga. will driveaspect ratio to the AR = +lo range. Contract NASI- 13694. Composite materials may raiseaspect ratio to about 11- 12 and practicallaminar €low-control system may furtherincrease aspect ratio to 14 or 16. *Mabey, Dennis G. : Some Remarks on the Desiqn more.Advanced technologyprovides significant ofTransonic Tunnels with Low Levelsof Flow reductionsin aircraft take-off gross weight, Unsteadiness. NASA CR-2722, Aug. 1976, 20 pp. energyconsumption, and direct operatingcost.

N79-25039# *NASA, LangleyResearch Center, Hampton, Va.

The principalsources of flowunsteadiness in the circuit of a transonic wind tunnelare pre- 19.*Douglas Aircraft Co.: Developmentof sented.Care must betaken toavoid flow separa- Technology forthe Fabrication of ReliableLaminar tions,acoustic resonances and largescale turbu- Flow ControlPanels on SubsonicTransports. NASA lence. Some problemsdiscussed are the elimina- CR-145125; MDC-J4546; Oct. 1976, 214 pp. tion of diffuserseparations, the aerodynamic designof coolers and the unsteadiness generated N77- 17038# in ventilated working sections. The feasibility ofusing porous composite *Royal AircraftEstablishment, Bedford, England. materials(Kevlar, Doweave, and Leno Weave) as NASA L-32158-A lightweight,efficient laminar flow control (LFC) surfacematerials is compared tothe metallic 319L stainless Dynapore surfacesand electron beam 17. Aircraft Fuel Efficiency Program. GPO Wpt. drilledcomposite surfaces. Areas investigated (GPO-57-010) for U.S. Senate(S-Rept-94-633) Comm. include: ( 1) selection of theLFC-suitable sur- on Aeronauticaland Space Sciences, 94th face materials, structural materials, andfabri- cationtechniques for the LFC aircraftskins; (2) aerodynamic static air flow test resultsin terms ofpressure drop through the LFC paneland 9 & . v the corresponding effective porosity; (3) struc- perturbations. A demonstration of the suitability --. ~ tural design definition and analyses of the of the numerical method for the investigation of panels; and (4) contamination effects on static stability and the initial growth of disturbances drop and effective porosity. Conclusions are is presented for small periodic perturbations. presented and discussed. For this particular case the numerical results can be compared with linear stability theory and experimental measurements. In this paper a number *McDonnell Douglas Corp, Long Beach, Calif. of numerical calculations for small periodic dis- Contract NASI- 14400 turbances are discussed in detail. The results are generally in fairly close agreement with linear stability theory or experimental 20. *Econ, Inc.: An Assessment of the Benefits measurements. of the Use of NASA Developed Fuel Conservative Technology in the U. S. Commercial Aircraft *Institut A fiir Mechanik, Universitiit, Stuttgart, Fleet. NASA CFt-148148 (Revised); Rept.-75-163-1, Germany. Oct. 1975, 04 pp.

376-232491 22. *Leonard, Fbbert W.; and Wagner, Richard D.: Airframe Technology for Energy Efficient Transport Cost and benefits of a fuel conservative Aircraft. Paper presented at SAE 1976 Aerospace aircraft technology program proposed by NASA are Engineering and Manufacturing Meeting, San Diego, estimated. NASA defined six separate technology Calif., NOV. 29-Dec. 2, 1976, 17 pp. elements for the proposed program: (a) engine component improvement (b) composite structures SAE 760929 A77-20234 (c) turboprops (d) laminar flow control (e) fuel conservative engine and (f) fuel conservative NASA has initiated a comprehensive Aircraft transport. There were two levels postulated: Energy Efficiency Program which is concerned with The baseline program was estimated to cost the development of approaches for reducing fuel $490 million over 10 years with peak funding in consumption in new aircraft of the 1980-2000 time 1980. The level two program was estimated to cost period. A review is presented of the airframe an additional $180 million also over 10 years. technologies selected for emphasis in the NASA Discussions with NASA and with representatives of program, taking into account an evaluation of the major commercial airframe maufacturers were their potential for reducing transport direct held to estimate the combinations of the tech- operating cost for derivative and new aircraft nology elements most likely to be implemented, the introduced by 1985. Technology for maintenance of potential fuel savings from each combination, and a laminar boundary layer in cruise offers great reasonable dates for incorporation of these new benefits in fuel efficiency and direct operating aircraft into the fleet. cost and may be ready for application to transports introduced in the 1990's. *Princeton, N. J. Contract NASW-2781 +NASA, Langley Research Center, Hampton, Va.

21. *Fasel, H. : Investigation of the Stability of 23. 'Herbert , 'Ih. : On the Stability of the Boundary Layers by a Finite-Difference Model of Boundary Layer Along a Concave Wall. Biennial the Navier-Stokes Equations. Journal of Fluid Fluid Dynamics Symposium on Advanced Problems and Mechanics, Nov. 23, 1976, Part 2, pp. 355-303. Methods in Fluid Dynamics, 12th, Bialowieza, Poland, Sept. 8-13, 1975. Arch. Mech. Stosow., A77-20041 vol. 28, no. 5-6, 1976, pp. 1039-1055.

The stability of incompressible boundary- A77-2937 1 layer flows on a semi-infinite flat plate and the growth of disturbances in such flows are investi- Various approaches for investigating the gated by numerical integration of the complete linear stability of the laminar boundary layer Navier-Stokes equations for laminar two- along a concave wall with respect to Ggrtler vor- dimensional flows. Forced time-dependent distur- tices are compared concerning their order in the bances are introduced into the flaw field and the two small parameters, wall curvature and inverse reaction of the flow to such disturbances is Reynolds number, as well as thetreatment of the studied by directly solving the Navier-Stokes curvature terms. Numerical results show sepa- equations using a finite-difference method. An rately the effects of wall curvature, streamline implicit f inite-dif f erence scheme was developed curvature and its finite extent on the neutral for the calculation of the extremely unsteady flow conditions. The influence of the growing boundary fields which arose from the forced time-dependent layer thickness on the stability characteristics disturbances. The problem of the numerical sta- is estimated and found to be of first order. bility of the method called for special. attention in order to avoid possible distortions of the *Freiburg, Universitaet, Freiburg im Breisgau, results caused by the interaction of unstable Germany numerical oscillations with physically maninqEu1

7 24.*Kutateladze, S. S.; and*Migirenko, G. S. Lockheed-Georgia OO., Jan. 17, 1977. (Avail- (editors):Investigations of BoundaryLayer Con- able to U. s. Gov't. AgenciesOnly) -trol. Novosibirsk - 1976. (InRussian.) In this digest are set out some results of X78-75877AD BO26 321L investigationsof various boundary layer controlling methodsincluding distributed suction, poly- *Lockheed-Georgia Co., Marietta, Georgia meric additionintroduction, gas saturationof boundary layer andthe formation of viscoelastic propertiesfor streamlined surfaces. 26. *Weiss, D. D.; and*Lindh, D. V.: Development of the Technologyfor the Fabrication of Reliable Most ofthe papers deal with the investi- Laminar Flow ControlPanels. Final Rept. NASA gationof transition of boundary layer into turbu- CR-145124;D6-44184; Feb. 1977, 119 pp. lenceand the development of measuring equipment andmethods. N77-18131#

Contents The resultsof a 5 months test program to evaluate LFC surface materials are reported. 1. Kolobov, B. P.; Migirenko, G. S.; and Requirements for LFC surfacesmoothness and flow Novikov, B. G.: Boundary-Layer Control by the were compiledfrom existing data. Various config- DistributedSuction. urations of porous,perforated and slotted materials were flowtested to determineif they would 2.Vedyakin, P. I.; Garipov, R. M.; and meet theserequirements. The candidate materials Novikov, B. G.: The Effectof Homogeneous Suction were thentested for susceptibility to clogging Through PerforatedSurfaces on Laminarand Turbu- and for resistance to corrosion. Of the materials lent BoundaryLayer. tested,perforated titanium, porous polyimide, and slotted assemblies demonstrated a much greater 3. On theEffect of Saturation on the Wall resistance to cloggingthan other porous mate- Turbulence. rials. Three conceptsfor installing LFC materials were studied. 4.Bogdevich, V. G.; andMalyuga, A. G.: SurfaceFriction Distribution in the Turbulent *Boeing Commercial Airplane Co., Seattle, Wash. BoundaryLayer Behind thePlace of Gas Injection. Contract NASI- 14407

5. Kobets, M. L.; andKobets, G. F.: The DragReducing Natural Polymers. 27. 'Meade, L. E.; *Kays, A. 0. ; fFerril1, R. s. ; and *Young, H. R.: Developmentof theTechnology 6.Vanin, Yu. P.; andMigirenko, G. S.: On for the Fabrication of Reliable Laminar Flow Con- theDistribution of Polymer Concentrationsin trol Panels.Final Technical F!ept., Apr.-Sept., Boundary Layer - 1976. NASA CR-145168, Feb.1977, 91 pp.

7. Semenov, B. N.: The Effect of Elastic N77-22178 Coverson a TurbulentBoundary Layer. Materials were assessedand fabrication tech- 8. Trifonov, G. F.: On Measurementof Skin niques were developedfor use in the manufacture Frictionin Dilute PolymerSolution Using Hot ofwing surface materials compatiblewith the Films. applicationof both aluminum alloys and nonmet- allic composites. The conceptsinvestigated 9.Belousov, P. Ya.; andEvseev, A. R.: includedperforations and slots in the metallic MultichannelLaser Doppler Velocimeter. test panelsand microporosity and perforations in thecomposite test panels.Perforations were 10.Voitenko, A. N.; andTetyanko, V. A.: On produced in the metallic test panels by the the Measurementof an IntermittencyCoefficient in electron beam process and slots were developed by Laminar-TurbulentTransition. controlledgaps between the metal sheets. Micro- porosity was produced in the composite test panels 11. Sobstel, N. B.; Tetyanko, V. A.; by theresin bleed process, and perforations were Sharapova, T. A.; andShtatnov, Yu. V.: On the produced by the fugitivefiber technique. Each of Formationof the Turbulent Boundary Layer. theseconcepts was fabricated into test panels, and air flow tests were conductedon the panels. *Instituteof Thermophysics , Academy of Sciences of the USSR, SiberianBranch Flow test results for each material specimen were compared withan analytically predicted vari- ablesuction criteria, andindicated acceptable 25. 'Kopkin, T. J.; and*Rife, C. D.: Laminar performancefor all butthe microporous composite Flow ControlBibliography. Rep. No. LG 77ER0018, specimens.Contamination and cleaning tests were conductedon selected electron beam perforated panels. Maximum increasesin pressure loss due to

8 /, -.- -_8'.. ++ contaminationof 23 percent were observed,and in ___-Boundary Layers Along Concave Curved Walls. Presentexat the ASME AppliedMechanics/ generalthe cleaning process successfully removed " thecontaminant. Further flow analysis included Bioengineering/FluidsEngineering Summer Confer- flow frictionfactor evaluation with good data ence,Yale Univ. , New Haven,Conn., June 15- 17; consolidationfor all test conditionsof electron 1977. Journal ofApplied Mechanics, vol. 44. beam perforationsand slotted test panels. Sev- March 1967, p. 11-17. eral samplesof theperforated composite panels were submittedto NASA alongwith material data ASME Paper No. 77-AH-4 A77- 2841 1 # sheets. Thispaper considers the effect of heating on Taylor-Grtlervortices in laminar boundary *Lockheed-Georgia Co., Marietta, Ga. layers. The effect of higher-order terms and the Contract NAS1- 14409 normal velocity componentof theprimary flow in thestability calculations has beendemonstrated. The findingsindicate that tern involvingthe 28. *Carter, James E. : STAYLAM: A FORTRAN Program higher-ordereffects of curvatureas well as the forthe Suction Transition Analysis of a Yawed normal component of theprimary flow become " Wing IaminarBoundary Iayer . NASA R3 X-740 13, increasinglyimportant at small wave numbers. The March 1977, 80 pp. effect of heating is to stabilize the flow to disturbances of long lateral wavelengthbut has a N77- 18390 destabilizing effect on shortwavelength disturbances. A computerprogram called STAYLAM is presentedfor the computation of the compressible *Ecolemlytechnique, Montreal, Canada laminarboundary-layer flow over a yawed infinite **ColoradoState Univ., Fort Collins, Colo. wing includingdistributed suction. This program is restrictedto the transonic speed range or less due tothe approximate treatment of the compres- 31. *Mojola, 0. 0.: Transitionin a Streamwise sibilityeffects. The prescribedsuction distri- Corner. AIAA Journal,vol. 15, March 1977, bution is permitted to changediscontinuously pp. 427-429. alongthe chord measured perpendicular to the wing leadingedge. Estimates of transition are made by A77-26736# consideringleading edge contamination, cross flow instability, and instability of theTollmien- Some aspects of natural and artificial tran- Schlichtingtype. A program listing is given in sition to turbulent flow ina right-angled stream- addition to user instructions anda sample case. wise corner formed by theintersection, at low subsonicspeed, of two smooth flatplates with *NASA, LangleyResearch Center, Hampton, Va. unsweptleading and trailing edges are analyzed. The importance of thisanalysis for wing-body junctions of aircraft is pointedout. The 29. *Gregorek, G. M.; 'Hoffmann, M. J.; **Payne, measurements were carriedout in a closed circuit H. E.; and**Harris, J. P.: Drag Evaluationof wind tunnelwith a freestreamturbulence of 0.03%. theBellanca Skyrocket 11. Presented at Society ofAutomotive Engineers, Business Aircraft Mtg. *IfeUniversity, Ife, Nigeria. Wichita, Kan., Mar. 29 - Apr. 1,1977, 13pp.

SAE Paper-770472 A77-37090 32. Volodin, A. G.; andZel'man, M. B.: Pairwise

~"Nonlinear- vteractionsof mllmien-Schlichtinp The BellancaSkyrocket 11, possessor of five Waves .~in Flows of the Boundary-Layer Type. worldspeed records, is a singleengine aircraft (Translatedfrom Izvestiya Akademii Nauk SSSR, withhigh performance that has been attributed to Mekhanika Zhidkosti i Gaza, No. 2, pp.33-37, a laminarflow airfoil and an all compositestruc- March-April1977.) Fluid Dynamics, vol. 12, ture.Utilization ofcomposite materials in the no. 2, et. 1977,pp. 192-196. Skyrocket I1 is uniquesince this selection was made to increase the aerodynamicefficiency of the A78- 22354 aircraft.Flight tests are inprogress to measure the overall aircraft drag and the wing section Fora flow of theboundary-layer type, the dragfor comparison with the predicted performance methodof a phase plane is used to investigate the ofthe Skyrocket. Initial results show thezero jointevolution of pair of Tollmien-Schlichting lift drag is indeed low, equalling 0.016. waves as a function of the R numbersand the frequencies. *Ohio State Univ., Columbus, &io **Bellanca Aircraft Engineering, Scott Depot , W. Va. 33. *Klineberg, J. M.: Technology forAircraft Grant NSG 1327 EnergyETficiency. Presented at InternationalAir TransportationConference, Wash., D. C., Apr. 4-6, 1977 , In the Proceedings,American Society of 30. *Kahawita, R. A.; and **Meroney, R. N.: The

"Influence ~ of Heating on the Stability of Laminar

! the position of the grids relative to the boundary layer start, a momentum loss in the boundary layer can be added.This effect of largefluctuation velocity componentsand nonuniformity of the flow A79- 14136 at the start of the boundarylayer was investigated detail. The investigationsled to some Sixtechnology programs for reducing fuel use in generalremarks about the influence of the free in U. S. commercialaviation are discussed. The stream turbulence level in low speed wind tunnel six NASA program are dividedinto three groups: measurements. Propulsion - enginecomponent improvement, energy efficientengine, advanced turboprops; Aero- *AerodynamischeVersuchsanstalt, Goettingen, West dynamics energyefficient transport, laminar - Germany flowcontrol; and Structures - compositeprimary structures.Schedules, phases, and applications of theseprograms are considered, and it is sug- 36.Laminar-Turbulent Transition. Fluid Dynamics gested that program results will be applied to Panel Symposium, heldin Lyngby,Denmark, May 2-4, currenttransport derivatives in the early 1980s 1977, AGAFD-CP-224, kt. 1977, 380 pp. and toall-new aircraft of the late 1980sand early 1990s. N78- 143 16# *NASA, Washington, D. C. Stability theory and prediction methods applied to fluid dynamic processesin laminar- transitionalflows were discussed.Twenty-eight 34. *Foss, R. L. : VeryLarge Aircraft - Tech- papers were given.Citations of some selected nologyand Operational Implications. Presented papersfollow. Morkovingave theintroductory atInternational Air TransportationConference, address(no. 37 inthis compilation) and alsothe Wash., D. C., April 4-6, 1977,Proceedings evaluationreport of the symposium (no.83 in this (A79-14126), Amer. SOC. of Civilmgineers, New compilation). York, 1977,pp. 172-196.

A79- 14137 37. *Morkovin, M. V.: Instability,Transition to Thispaper discusses future growth trends of Turbulenceand Predictability. Presented at AGARD Fluid Dynamics Panel Symposium on Laminar- commercial aircraft, starting with historical patternsthat indicate the changes in airplane TurbulentTransition (AGARD-CP-224),Lyngby, Denmark, May 2-4, 1977. AGARD-AG236, July 28, physicaldimensions and weight that haveoccurred overthe last severaldecades. Reasons for the 1978, 38pp. observedgrowth are reviewed. Size of today's largeaircraft is summarized forreference. Pro- N78-31401# jections ofcommercial needs forthe future are outlined.Their potential impact on future air- A concisestate of the art review on the craft growth patterns is shown interms ofadded phenomenon of transition which constitutedthe range,payload, and change in cruise speed. The openingaddress is presented.Various instability consequencesand benefits of switching to alter- mechanisms leadingto transition are proposed and natefuels, returning to turboprop power plants, discussed. A variableinsight is providedbased on existingexperimental evidence and postulated adoptingairships, or revitalizingsea planes is examined.Benefits of advancedtechnology con- flowstructures. Critical questions are asked sidering new structuralmaterials, laminar flow relatingto the conceptual foundation on which control,and advanced flight control systems is much of thetransition effort is based. To discussed.Typical aircraft of thefuture are enhanceunderstanding of the basic mechanismsand illustrated. From thiscollection, a likely list processes,detailed microscopic experiments are of candidatesthat may be operationalin 1995 is encouragedto increase the data base. offered,together with the rationale for their selection. *IllinoisInstitute of Technology,Chicago, Ill.

*Lockheed-California Co., Burbank, Calif. 38. *Saric, W. S.: and'Nayfeh, A. H.: Nan- parallelStability ofBoundary Layers with 35. *Meier, H. U.: The Effect of Velocity PressureGradients and Suction.In AGARD Laminar- Fluctuationsand Nonuniformities in the Free TurbulentTransition. Lyngby,Denmark, May 2-4, Stream on the Boundary LayerDevelopment. Pre- 1977, AGARD-CP-224 (N78-14316#), kt. 1977. sentedat the Symposiumon TurbulentShear Flows, 21 PP. Univ. Park,Pa., April 18-20,1977. In theProceedings, Vol. I, (A77-33806),1977. N78- 14322# pp.10.35-10.41. An analysis is presentedfor the linear non- A77-33853# parallel stability ofboundary layerflows with pressuregradients and suction. The effect of the The influence of gridgenerated wind tunnel boundarylayer growth is included by usingthe turbulence was studied. It was found that due to method of multiplescales. The presentanalysis

10 is compared with those of Bouthierand Gaster and nearly the same value(about 10) in many different the roles of the differentdefinitions of the cases for flowswith low freestream turbulence amplification rates are discussed. The resultsof levels. An attempt is made to includethe effects thesetheories are comparedwith experimental data of higherfree stream turbulence levels by allow- for theBlasius boundary layer. Calculations are ing the critical amplification factor to decrease presentedfor stability characteristics of with increasingfree stream turbulence. boundarylayers with pressure gradients and non- similarsuction distributions. *Dept.of Aerospace mgineering,Technische Hogeschoal,Delft (The Netherlands) *VirginiaPolytechnic Institute and State University,Blacksburg, Va. Grant NsG-1255 41. Poll, D. I. A.: Leading Edge Transition on Swept Wings. In AGARD-CP-224, Laminar-Turbulent Transition, May 2-4, 1977, (N78-143161, Oct. 1977, 39.*Gougat, Pierre;and Wartin, mancoise: The 11 PP. Influence.of a Periodic Wall Deformationon the N78- 143361 ~~Development-.of Natural Instabilities Leadingto a Transition.(Influence d'une Deformation Periodiquede Paroi sur le Development des The behaviorof the swept wing attachment InstabilitiesNaturelles conduisant a la line boundarylayer has been studied experi- Transition) . In AGARE-CP-224, Laminar-Turbulent mentally. Two dimensionaltrip wires andturbu- Transition, May 2-4, 1977,(N78-14316) Oct. 1977, lent flat plate boundarylayers have been used as 9 pp. (InFrench. ) sourcesof disturbance and a widerange of con- ditionshas been covered, ensuring that the N78-14333# results are directlyapplicable to full scale flightsituations. Simple criteria havebeen The natural instabilities whichoccur in the deducedand those allow the state of theattach- laminarboundary layer of a deformable wall are ment line boundary layer to be determinedfor a constituted by a series of intermittent waves. A givengeometry and freestream conditions. The spectral analysis of thesefluctuations reveals validity of some of theprincipal results has thefrequencies and coefficients of amplifications beenextended to high Mach numbers forthe of natural instabilities are identical to those adiabatic wall case. Sample calculations show predicted by thestability theory. A deformation that most ofthe present generation of civil ofthe wall doesnot change the structure of the aircraft haveturbulent attachment lines in the phenomena; it merelyintroduces a degreeof cruisecondition. Although some benefit may be exterior velocity whichprovokes an amplification gained by a removalof root disturbances and the or attenuation of theinstabilities. The effect maintenanceof a smooth leadingedge the tolerable of a static deformationof the wall on the forma- roughnessheights are so small that it seems tion and amplifiction ofboundary layer insta- unlikelythat turbulence can be preventedwithout bilities was studiedin relation to the gradient some formof boundary layer suction. of exteriorspeed.

*Laboratoire d'Aerothermique duC.N.R.S., Meudon, 42. *Finson,Michael L.: On theApplication of France. Second-OrderClosure Models to BoundaryLayer Transition.In AGARD-CP-224, Laminar-Turbulent Transition, May 2-4. 1977,(N78-14316), Oct. 1977,

40. *Vaninsen,-. J. L.: Transition.Pressure ~~ ~ 6PP. Gradient,Su.ction, Separation and Stability Thee-ry. In AGARE-CP224, Laminar-Turbulent N78- 14338# Transition, May 2-4, 1977,(N78-14316). Oct. 1977. 15 pp. Second-orderclosure models offer several potentialadvantages for the study and prediction N78- 14335# ofboundary layer transition. The required closureapproximations can be formulated to A semi-empiricalmethod is presentedfor the representan adequate physical description of the predictionof transition in two-dimensional incom transitionprocess. A fiveequation model is pressibleflows with pressure gradient and suc- presentedfor fluctuating variables. It is argued tion.Included is the case of thelaminar separa- thatadequate closure techniques are availablefor tionbubble, where transition is precededby theproduction, dissipation, and diffusion terms. laminarseparation. The methodemploys linear Improvedclosure schemes are suggested,and a stability theory to calculatethe amplification model is also presentedfor the manner by which factor sigma forunstable disturbances in the surfaceroughness elements disturb the boundary laminarboundary layer (sigma is defined as the layer.Calculations have been obtained for two naturallogarithm of the ratio between theampli- by-passsituations where the initial fluctuation tude of a disturbance at a giveninstant or posi- levels are relativelyhigh, due either to free tion to theamplitude at neutralstability). It stream turbulence or surfaceroughness, and the is foundthat at theexperimentally determined transition position the calculated amplification factorfor the critical disturbancesattains

" ...... " P?

results are in reasonableagreement with wind The prospects forCanadian commercial air- tunnelobservations on flat plates. lines from the present to theend of the century are assessed. Noise regulation andretrofitting, *PhysicalSciences, Inc., Woburn, Mass. active controltechnology, laminar flow control, regenerativeturbines, and multi-blade turboprop withblades swept like wings are cited in discuss- 43. *Whitfield,Jack D.; and*Dougherty, ing the processes of fleet replacementand acqui- Sam N. , Jr. : A Surveyof mansitionResearch sition. The likelihoodthat Canadian airlines at AEDC. In AGAFG-CP-224, Laminar-Turbulent will acquire the A300 Airbus, the Concorde, or the Transition, May 2-4, 1977,(N78-14316), Oct. proposedMcDonnell Douglas DC-9-55, the being 7N7 1977. 20 pp. and7x7, or the BritishAircraft Corporation BAC-X- 11 is considered. N78- 14340# *AirCanada, Montreal, Canada Experimentalresearch on transitionReynolds numbersconducted in a large number ofground test facilities is surveyed.Facilities surveyed 46. *Frisbee, L. E.; and *Hopps, R. H.: includedprimary wind tunnelsused for aerodynamic ChangingHorizons for Technical Progress xnAir testing at subsonic,transonic, supersonic, and Transportation.In "The Placeof Aviation in hypersonicconditions. Measurements have been Society";Proceedings of the15th Anglo-her. made on conesand planar bodies, flat plates and AeronauticalConference, London, mgland, May 31- hollowcylinders. The primarymotivation for this June 2, 1977,(A77-41926). Royal Aero. Society. researchspanning nearly 25 yearshas been to 23 PP. verifythe adequacy of the facilities to simulate flightconditions. This necessarily entailed the A77-41946# studyof free stream disturbancesin wind tunnels and therole these disturbances play in altering Some ofthe most promisingpotential tech- transition Reynolds number whichmust be con- nologicaldevelopments in the air transportation sidered when scaling Reynolds number sensitivity field are discussed,including improvements in data. airframe design, aircraft engines,and active controlshardware. Major obstaclesto these *Propulsion Wind Tunnel Facility, ARO, Inc., relatively short term developments are con- Arnold Air ForceStation, Tenn. sidered.Special attention is givento the problem offuel economy. Technologiesrequiring Sponsored by AEDC a longer time-scale forresearch anddevelopment, includingadvanced turboprop engines, all-wing concepts,and laminar flow control, are outlined. 44. *Kelly,Robert E.: The Formationand The potentialimpact of hydrogen-based power Stabilityof Longitudinal Roll Vortices in Shear plants on thedevelopment of super- and hypersonic Flows. Final Rept. June 1972-May1, 31, 1977, transports is examined. UCLA-Eng.-7737, May 31,1977, 18 pp. *Lockheed-California Co., Burbank, Calif. AD-A04869 1 N78- 18367#

Longitudinal roll vorticesoccur frequently 47. *Kachanov, Yu. S.; *Kozlov, V. V.; and inshear flows. Although they are most commonly *Levchenko, V. Ya.: NonlinearDevelopment of a driven by body forces(either centrifugal or Wave in a BoundaryLayer. (Translated from buoyant),they are also observedduring transition Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti in homogeneous boundarylayers. Under theabove i Gaza, No. 3, pp. 49-58, May-June, 1977.) Fluid grant,various investigations have been made of Dynamics, Jan.1978, pp. 383-390. theirformation and, for the case of thermally drivenvortices, their own instability.This Inrecent years definite progress hasbeen report summarizes theresults obtained. More achievedin the construction of theoreticalmodels detailedresults can be foundin the journal ofnonlinear wave processeswhich lead to a tran- publicationsreferred to in the report. sition fromlaminar to turbulentflow. At the same time, there is a shortageof actual experi- funiv.of California, Los Angeles,Calif. mental material, especiallyfor flows in a Contract DA-ARO-D-31-124-72-Gl68 boundarylayer. Fairly thorough experimental studieshave been carried out only on the initial stage of thedevelopment of disturbances in a 45. *MacDonald, I. S.: CommercialAviation Future boundarylayer, which is satisfactorilydescrib- Progress,Programs, Proposals, and Problems - A able by thelinear theory ofhydrodynamic stabi- Prognosis/W. !?upert TurnbullLecture. Presented lity.In evaluating the theoretical modelsof at the CanadianAeronautics and Space Institute subsequentstages of thetransition, investigators AnnualGeneral Meeting, Quebec City, Canada, havebeen forced to turnchiefly to much earlier May 17, 1977. CanadianAeronautics and Space experimentscarried out by theUnited States Journal,vol. 23, Nov.-Dec., 1977, pp. 338-345. NationalBureau of Standards, in which the main attention was concentrated on thethree- A78- 18034# dimensionalstructure of the transition region.

12 ,g '.2. The presentinvestigation was undertakenfor the 'Douglas Aircraft Co., Inc., Long Beach, Calif. " purposeof obtaining detailed data on the struc- Contract NASI- 14498 tureof the flowin the transitionregion when there is disturbancein the laminar boundary layer Note: There is a "User's Guide for Program Main of a two-dimensional wave. Inorder to make the to CalculateCompressible Laminar Boundary Layers two-dimensionalnonlinear effects stand out more withSuction on Swept andTapered Wings" which clearly, the amplitudeof the wave was specified perhapscould be obtainedfrom the authors or from to be fairlylarge from the very outset. In con- DouglasAircraft Co. trast to earlier investigations, the main attention was centeredon the study of the spectral compositionof the disturbance field. 50. 'Lange, R. H.; and*Bradley, E. S.: Para- metric Studyof Advanced Long Range Military/ *Institute of Theoreticaland AppiedMechanics, Commercial Cargo Transports.Presented at the SiberianDivision of the Academy ofSciences, USSR AIAA Aircraft Systems L TechnologyMeeting, Seattle, Wash., Aug. 22-24, 1977, 8 pp.

48. fpfenninger, Werner:Laminar Flow Control AIAA-77-1221 A77-44322 Laminarization.Special Course on Concepts for DragReduction. Held at the von Karman Inst., This paperdescribes the results ofLockheed mode-St-Genese,Belgium, Mar. 28-Apr. 1, 1977. parametricdesign studies of the performance and AGARD-R-654, June1977, p. 3-1 - 3-75. economicsof advanced technology military/ commercialcargo transports envisioned for opera- N77-32094# tionin the 1985and 1995 time period. The design parameters investigatedinclude payloads from A practicalaerodynamically and structurally 220,000 to 550,000pounds and ranges from 3,500 to reasonablyefficient laminar flow control (LFC) 5,500 nauticalmiles. All configurationshave suction method,removing the slowest boundary supercriticalwings, advanced composite materials, layerparticles through many closedspaced fine relaxedstatic stability, and low noiselevels. slots, was developedand subsequently applied to a The application oflaminar flow control (LFC) second F94 LFC wingglove inflight: 100 percent technology on theperformance ofan advanced laminarflow was observed up to the F94 test militarytransport is also presented. limit. Laminarflow on LFC wings inflight is thuspossible at a much higherReynolds number *Lockheed-Georgia Co., Marietta, Ga. thaneven in the best low turbulencetunnels as a result of thenegligible influence of the atmos- phericmicroscale turbuence on transition. The 51.*Srokowski, A. J.; and**Orszag, S. A.: MaaS F94 LFC glovecomparison experiments, with Flow Requirementsfor LFC Wing Design. AIAA Air- suctionstarting at 0.03~and 0.4c, verifiedthe craft Systemsand Technology Meeting, Seattle, theoreticallypredicted bounday layerstabil- wash., Aug. 22-24, 1977, 16 pp. ization by suctionstarting at O.O8c, thus main- taininglaminar flow at substaniallyhigher CL AIAA-77- 1222 A77-44323# as compared to boundary layerstabilization by flowacceleration; i.e., geometryalone without The problemof determining optimum suction suctionupstream of 0.4~. mass flowrequirements for LFC wings is addressed. Some previousmethods €or predictingthe extent *NASA, LangleyResearch Center, Hampton, Va. oflaminar flow over swept wings with suction are brieflyreviewed. These rangefrom the purely empirical to those utilizing tabulated linear 49.*Kaups, Kalle; and*Cebeci, Tuncerf stabilitycomputations. The present method is CompressibleLaminar Boundary Layers With Suction described. This method solvesthe linear, incom- on Swept andTapered Wings. Journalof Aircraft, pressiblestability equations by spectral tech- Val. 14, July 1977,pp. 661-667. niques. me maximum temporalamplification of boundarylayer crossflow and 2-D disturbances is A77- 37940# determinedfor waves of a givenfrequency. Group velocities are used to integratethese amplifica- Inthis paper we present a numericalmethod tion rates alongthe wing to yieldthe logarithmic forsolving the compressible laminar boundary- amplitude ratio or "N factor" ofthe distur- layerequations with suction on swept andtapered bance. The "N factor"calibration of a computer wings. The methodemploys an efficienttwo-point codeutilizing this method is described,using finite-difference method to solve thegoverning experimentallydetermined transition data. The equations,and a veryconvenient similarity trans- method is shown to be as consistent as previously formationwhich removes the wall normalvelocity used"fixed wavelength" methods. as a boundarycondition and places it into the governingequations as a parameter. Inthis way *NASA, Langley-search Center, Hampton, Va. the awkward nonlinearboundary condition which **Mass. Inst.of Tech.,Cambridge, Mass. couples all thevariables is avoided. lb test and demonstrate the method, we present a sample calculation for a typical laminar-flow-control ( LFC) wing.

13 52. 'Hopps, R. H. : FuelEfficiency - Where We hasbeen conducted to exploit recentadvances in materials andmanufacturing technology for the ports. InProceedings of the Canadian Symposium fabrication of reliable porous or perforated LFC onEnergy Conserving Transport Aircraft, Ottawa, surfacepanels compatible with therequirements of Canada,Oct. 3, 4, 1977,(A78-31301), PP. 6-1 subsonictransport aircraft. Attention is given to 6-16. to LFC design criteria, surface materials, surface concepts, the useof microporous composites, per- A78-31307# forated composites, andperforated metal. The descrihed program was successful in that fabrica- Consideration is given to the 1980s jet- tion processes were developedfor producing pre- transportmarket with emphasis on narrow-body vs dictableperforated panels both of composite and wide-body aircraft,the benefits of increasedsize of metal. andcapacity and the feasibility of superlarge aircraft.Technology of the 1980s relating to *Lockheed-Georgia, Marietta, ra. span,active controls andcomposites is briefly NAS1-14409 reviewed. Three potentialtechnologies for the 1990s are discussed:laminar flow control, advancedturboprops and liquid hydrogen. It is 55. *Banner, 'Ibm F., Jr.; *Pride,Joseph D., Jr.; notedthat the technology of the 1980s will not and*Fernald, William W.: Aircraft EnergyEffi- offerdramatic improvementsover all the aircraft ciencyLaminar Flow Control Wing DesignStudy. flowntoday; large improvements can be offered NASA TM-78634, OCt. 1977, 34 pp. onlyin comparison with the older narrow-body aircraft. N78- 13042#

*Lockheed-California Co., Burbank, Calif. An engineeringdesign study was performed in whichLaminar Flow Control (LFC) was integrated into the wingof a commercial passengertransport 53. *Klineberg, J. M.: The NASA Aircraft Energy aircraft. A baselineaircraft configuration was Efficiency Program. InProceedings of the selected and the winggeometry was defined. The Canadian Symposium on EnergyConserving Transport LFC system,with suction slots, ducting, and suc- Aircraft, Ottawa, Canada, Oct. 3-4, 1977, tion pumps was integratedwith the wing struc- (A78-313011, pp 1-1 to 1-32. ture. The use of standard aluminum technologyand advancedSuperplastic Formed-Diffusion Bonded A78-31302# (SFDB) titaniumtechnology was evaluated. The resultsof the design study show thatthe LFC sys- The objective of the NASA Aircraft Energy tem can be integratedwith the wing structure to EfficiencyProgram is to accelerate thedevelop- provide a structurallyand aerodynamically effi- ment ofadvanced technology for more energy- cient wing for a commercial transport aircraft. efficientsubsonic transport aircraft. This program will haveapplication to currenttransport *NASA, LangleyResearch Center, Hampton, Va. derivativesin the early 1980sand to all-new aircraftof the late 1980sand early 1990s. Six mjor technologyprojects were definedthat 56. *Kobavashi... R. : and *Kohama. Y. : Tavlor- couldresult in fuel savings in commercial GGrtler Instabilityof Compressible Boundary aircraft:(1) hgine Component Improvement, Lavers. AIAA Journal,vol. 15,no. 12. Dec. 1977. ( 2)Energy Efficient Engine, ( 3) Advanced Turbo- pp. 1723-1727. props,(4) hergy Efficiency Transport (aero- dynamicallyspeaking), (5) Laminar Flow Control, The purposeof this paper is to consider and (6) CompositePrimary Structures. analytically how compressibilityof a fluid will affect the instability oflaminar boundary layers *NASA, Washington, D.C. alongslightly concave walls leading to theonset oflongitudinal vortices. Neutral stability curvesrepresenting the relation of the GErtler 54.*Meade, L. E.: Material Development for parameterto the dimensionless wavenumber of the Laminar Flow Control Wing Panels.Presented at longitudinalvortices and also distributionsof the9th National Technical Conference of the thedisturbances at theonset of thevortices are SOC. forthe Advancement of Material and Process presented. The results show thatthe critical Engineering, "Materials andProcesses, In Service value of the Gortler parameter increasesabout Performance"(A78-25176), Atlanta, Ga., Oct. 4-6, 1.6 times as thefreestream Mach number varies 1977,pp. 305-312. from 0 to 5 in the case of a thermallyinsulated wall. Effects of temperature ratio (wall temper- A78-25200 ature to freestreamtemperature) in cases of an isothermalwall are also discussed. The absenceof suitable porous materials or techniquesfor the economic perforationof surface *Tohoku Univ.,Sendai, Japan materials haspreviously restricted the design of laminarflow control (LFC) wingpanels to a con- siderationof mechanically slotted LFC surfaces. A description is presentedof a programwhich

14 57.Advancing Transport Aircraft Technology AerospaceSciences Meeting, Huntsville, Ala., Towards2000. Interavia,vol. 32, Dec. 1977, Jan. 16-18, 1978,9pp. pp.1219-1223. AIAA-78-203 A78-22597 A78-17135 The stability of a two-dimensional,inconr Innovationsin commercial aircraft are fore- pressible houndarylayer over a perforatedsurface castfor the 1980sand 1990s: attention is given is examined. The spacing of theperforations is to improvements inaerofoil design, the use of assumed to be small compared to the wavelength of compositesto reduce airframe weight, the reduc- thedisturbances. If, under the perforations, tion of specificfuel consumption,and reconsid- there exists a chamber thatpermits traveling eration of theturboprop. Active ailerons, wing waves toexist, it can,under certain conditions, tipextensions, high-aspect ratio wings, super- stabilizethe flow. Ifinstead there exist small critical wing designs,and laminar flow control chambers thatsustain compressible waves created arediscussed. Advanced powerplantsunder inves- by thedisturbance in the boundarylayer, their tigation,in addition to turboprops,include effect on the stability of theflow is negligible, improvedhigh bypass ratioengines, variable cycle forthe range of frequencies of interest. engines, and liquid hydrogen power systems. *Lockheed-Georgia,Marietta, Ga.

58. *Benney, David J.; and*Orszag, Steven A.: Stability Analysis for Laminar Flow Control - 61.*Sturgeon, R. F.: The Developmentand Part I. NASA CR-2910, kt. 1977, 90 pp. .Evaluation of Advanced Technology Laminar-Flow- ControlSubsonic Transport Aircraft. AIAA 16th N78- 12363 AerospaceSciences Meetinq, Huntsville, Ala., Jan. 16-18, 1978,9pp. Thisreport develops the basic equations for thestability analysis of flowover three- AIAA-78-96 A78-52626 dimensionalswept wings and then surveys numerical methods fortheir solution. The equationsfor A study was conducted toevaluate the tech- nonlinearstability analysis ofthree-dimensional nical andeconomic feasibility of applyinglaminar disturbancesin compressible, three-dimensional, flowcontrol (LFC) tothe wingsand empennage of non-parallelflows are given. Efficient and accu- long-rangesubsonic transport aircraft for initial ratenumerical methods for the solutions of the operationin 1985.For a designmission range of equations of stabilitytheory are surveyed and 5500 n.mi.,advanced technology LFC andturbulent- analyzed. flowaircraft were developedfor a 200-passenger payload,and compared on the basis of production *CambridgeHydrodynamics, Inc. , Cambridge, Mass. costs,direct operating costs, and fueleffi- Contract NASI- 14427 ciency.Parametric analyses were conductedto establish optimum geometry,advanced system con- (Note:For Part 11, seecitation #184 inthis cepts were evaluated,and configuration varia- bibliography. ) tions maximizing theeffectiveness of LFC were developed. The finalcomparisons include consideration of maintenancecosts and procedures, 59. Kozlov, V. V.; Levchenko, V. Ya.; Maksimov, manufacturingcosts and procedures,and opera- V. P.; Rudnitskii, A. L.; andShcherbakov, tionalconsiderations peculiar to LFC aircraft. V. A.: Investigation ofViscous Fluid Flow at a SuctionSlit. Tsagi Uch. Zap., vol. 8.' no.1, *Lockheed-Georgia Co., Marietta, Ga. 1977,pp. 130-135. (Russiantext.) Contract NAS1- 13694

A79-12142 62. *Hage, R. E.; and*Stern, J. A.: The Chal- The flowof a viscousincompressible fluid lenge of Advanced Fuel-ConservativeAircraft - A along a platewith a narrow suction slit is Manufacturer's View. 14th Annual AIAA Meetingand studiedtheoretically andexperimentally. A TechnicalDisplay, Wash. D.C., Feb.7-9, 1978, numericalsolution of theNavier-Stokes equations 18 PP. is obtained,treating the mainstream simulta- neouslywith the flow within the slit, and taking AIAA-78-362 A78-24034# thestabilized flow as the boundary condition withinthe slit. Inthe experimental part of the Costs andtechnological problems associated study, a laser anemometer is used to measure the withadvanced fuel-conservative aircraft are dis- longitudinalvelocity component at various discussed,with particular attention given to the tancesfrom the slit and forvarious suction modes current NASA Aircraft Ehergy Efficiency (ACEE) andvarious mainstream conditions. Good agreement program,which focuses on enginecomponent betweentheory and experiment is noted. improvement,turboprops, laminar flow control and composites.In addition to the results of the ACEE program, aircraftmanufacturers will need to 60.*Lekoudis, S. G.: Stability of Boundary dealduring the next decade with the noise Layers Over Permeable Surfaces. AIAA 16th requirementsestablished by FAR Part 36. Due to

15 highcosts and noise considerations, Dc-8 and E707 N78-270668 fleets are expectedto be replaced by the 198Os, andthe demand for fuel-efficient aircraft in the Applicationof laminar flow control tech- 100- to 200-seatcategory will be significant. nology to future CTOL longrange transport air- Fuselagecross-sections for such a category are craft was considered.Topics covered include: considered; a comparisonof theeffectiveness of (1)airfoil developmentand test; (2) development twin-jets and tri-jets for medium-range transport andimprovement of design methods; (3) evaluation is alsoreported. ofleading edge contamination; and (4) laminar flowcontrol system definition and concept *Douglas Aircraft Co., mng Beach, Calif. evaluation.

*NASA, LangleyResearch Center, Hampton, Va. 63. *Wilson, S. D. R.; and*Gladwell, I.: The Stability of a Two-Dimensional StagnationFlow to Three-DimensionalDisturbances. Journal of Fluid 66. *Peterson,John B., Jr.; and**Fisher, Mechanics,vol. 84, Part 3, Feb.13, 1978, David F.: FlightInvestigation of Insect Contam- pp.517-527. ination and Its Alleviation.Presented at the CTOL TransportTechnology Conference, Langley A78-25168 ResearchCenter, Hampton, Va., Feb. 28 - Mar. 3, 1978. NASA CP2036,Part I, pp. 357-373, Experimentshave shown thatthe two- June 1978. dimensionalflow near a forwardstagnation line may be unstableto three-dimensional disturbances. N78-27067# The growingdisturbance takes the form of secondaryvortices, i.e. vortices more or less An investigation ofleading-edge contamina- parallelto the original streamlines. The insta- tion by insects was conducted at the NASA Dryden bility is usuallyconfined to the boundary layer FlightResearch Center with a JetStarairplane andthe spacing of thesecondary vortices is of instrumentedto detect transition on theoutboard theorder of theboundary-layer thickness. This leading-edgeflap and equipped with a system to situation is analysedtheoretically for the case wash theleading edge in flight. The results of of infinitesimaldisturbances of the type first airline-typeflights with the JetStar indicated studied by Gb’rtler and Hamerlin.These are dis- thatinsects can contaminate the leading edge turbancesperiodic in the direction perpendicular duringtakeoff and climbout at large jet airports tothe plane of theflow, in the limit of infinite inthe United States. The resultsalso showed Reynolds number. It is shown thatthe flow is thatthe insects collected on theleading edges at always stableto these disturbances. 180 knotsdid not erode at cruise conditions for a laminarflow control airplane and caused premature *Department of Mathematics, Univ.of Manchester, transition of thelaminar boundary layer. None of mgland thesuperslick and hydrophobic surfaces tested showed any significantadvantages in alleviating theinsect contamination problem. While there may 64. CTOL TransportTechnology - 1978. A confer- beother solutions to the insect contamination enceheld at LangleyResearch Center, Hampton, problem,the results of these tests with a washer Va., Feb. 28 - March 3, 1978. system showed that a continuouswater spray while NASA CP2036,Pt. I, June1978, 516 pp. encounteringthe insects is effectivein prevent- N78-27046# inginsect Contamination of theleading edges. NASA CP2036, Pt. 11, June1978, 468 pp. N79- 10097# *NASA, LangleyResearch Center, Hampton, Va. **NASA, Dryden FlightResearch Center, Edwards, Technologygenerated by NASA and specifically Calif. associatedwith advanced conventional takeoff and landingtransport aircraft is reported.Topics coveredinclude: aircraft propulsion; structures 67.*Srokowski, Andrew J.: Development of and materials; andlaminar flow control. Advanced Stability TheorySuction Prediction Tech- niquesfor Laminar Flow Control.Presented at A session on laminarflow control addressed the CTOL TransportTechnology Conference, Langley insectcontamination and alleviation;suction pre- ResearchCenter, Hampton, Va., Feb. 28 - Mar. 3, dictiontechniques; porous materials; andlaminar 1978. NASA CP2036,Pt. I, pp. 375-394, flowapplications. June1978.

Note:Selected papers from this conference N78-27068# follow. The problemof obtaining accurate estimates ofsuction requirements on sweptlaminar flow con- 65. *Muraca, Ralph J. : Laminar Flow Control trol wings was discussed. A fastaccurate cow Overview.Presented atthe CTOL Transport Tech- puter codedeveloped to predictsuction require- nologyConference, Langley &search Center, ments by integratingdisturbance amplification Hampton, Va.,Feb. 28 - Mar. 3,1978. rates was described.Assumptions and approxima- NASA -2036, Part I, pp. 349-356, June 1978. tionsused in the present computercode are

16 flowconditions on the swept atedwith operation of LFC aircraft,including their validity. accumulationof insects at low altitudesand environmentalconsiderations. *NASA, LangleyResearch Center, Hampton, Va. *Boeing Commercial Airplane Co., Seattle, Wash.

68. *Allison,Dennis 0.; and'Dagenhart, John R.: design^ of a Laminar-Flow-ControlSuper- 70. *Sturgeon, R. F. : Toward a Laminar-Flow-Con- critical nirfoilfor a Swept Winq. Presented at trol Transport.Presented at the CTOL Transport the CTOL TransportTechnology Conference, Langley TechnologyConference, Langley Research ResearchCenter, Hampton, Va., Feb. 28 - Mar. 3, Center, Hampton, Va. , Feb. 28 - Mar. 3, 1978. 1978. NASA CP-2036, Part I, pp. 395-408, NASA CP2036,Part I, pp. 449-495, June1978. June 1978. N78-27071# N78-27069# Analyses were conducted to define a practical An airfoil was analyticallydesigned and designfor an advanced technology laminar flow analyzedfor a combinationof supercritical flow control (LFC) transportfor initial passenger andlaminar flow control (LFC) by boundarylayer operationin the early 1990's. Mission require- suction. A shocklessinverse method was used to ments,appropriate design criteria, and levelof designan airfoil andan analysis method was used technologyfor the study aircraft were defined. in lower surfaceredesign work. The laminarflow The characteristics of theselected configuration pressuredistributions were computed without a were established,aircraft and LFC subsystems boundarylayer under the assumption that the lami- compatible with themission requirements were narboundary layer would bekept thin by suction. defined,and the aircraft was evaluatedin terms Inviscidcalculations showed that this 13.5 per- offuel efficiency. A wingdesign integrating centthick airfoil has shockless flows for con- the LFC ductingand metering system into advanced ditions at andbelow thedesign normal Mach number compositewing structure was developed,manufac- of 0.73 and thedesign section lift coefficient turingprocedures for the surface panel design of0.60, and that the maximum local normal Mach were established, andenvironmental and structural number is 1.12 at thedesign point. The laminar testingof surface panel components were boundarylayer instabilities can be controlled conducted. Test resultsrevealed a requirement withsuction but the undercut leading edge of the for relatively minorchanges inthe manufacturing airfoil provides a low velocity,constant pressure proceduresemployed, but have shown thegeneral coefficientsregion which is conducive to laminar compatibility ofboth the selected design and the flowwithout suction. The airfoil was designed to useof composite materials withthe requirements be capableof lift recoverywith no suction by the of LFC wingsurface panels. deflection of a small trailing edgeflap. *Lockheed-Georgia Co., Marietta, Ga. *NASA, LangleyResearch Center, Hampton, Va. Contract NAS1-14631

69.*Gratzer, L. B.; and*Georqe-Falvy, D.: 71.'Pearce, Wilfred E.: Application ofPorous -Application . ." of Laminar. Flow Control Technology Materials €or Laminar Flow Control.Presented at to Long-Range TransportDesign. Presented at the the CTOL TransportTechnology Conference, Langley CTOL TransportTechnology Conference, Hampton, ResearchCenter, Hampton, 'Va., Feb. 28 - Mar. 3, Va., Feb. 28 - March 3,1978, NASA -2036, 1978. NASA CP2036,Part I, pp. 497-522, Part I, pp.409-447, June 1978. June 1978.

N78-27070# N78-27072#

The impact oflaminar flow control (LFC) Fairly smoothporous materials were elected technology on aircraftstructural design concepts forstudy: Doweave; Fibermetal; Dynapore; and andsystems was discussedand the corresponding perforatedtitanium sheet. Factors examined benefits were shown in terms of performanceand include:surface smoothness; suction characteris- fuel economy. Specifictopics discussed include: tics; porosity;surface impact resistance; and (1)recent advances in laminar boundary layer straincompatibility. A laminarflow control developmentand stabilityanalysis techniques in suctionglove arrangement was identifiedwith terms of suctionrequirements and wing suction material combinationscompatible with thermal surfacedesign; (2) validation of theoryand real- expansionand structural strain. istic simulationof disturbances and off-design conditions by wind tunneltesting; (3) compatibil- *Douglas Aircraft Co., Inc.,Santa Monica, Calif. ity of aerodynamicdesign of airfoils andwings with LFC requirements; (4) structuralalternatives involvingadvanced alloys or composites in corn 72.'Nagel, A. L.: Studiesof Advanced Transport binations made possible by advanced materials pro- Aircraft. Presented at the CTOL Transportwch- cessing andmanufacturing techniques; (5) addition nologyConference, Langley Research Center, ofsuction compressor and drive units and their location on theaircraft;. and (6) problems associ-

17 Hampton, Va., Feb. 28 - Mar. 3, 1978. NASA pastaccomplishments and milestones going back to CP2036,Part 11, pp.951-982, June1978. the early NACA years are dealt with in a broad- brush way to give a better perspective of current N78-29064% developmentsand programs. In additionto the historicalperspective, a shortdescription of the Studieshave been made ofseveral concepts facilities which are now being used in the airfoil for possible futureairplanes, including all-wing program is given. This is followed by a discus- distributed-loadairplanes, multi-body airplanes, sion of airfoildevelopments, advances in airfoil a long-rangelaminar flow control airplane, a designand analysis tools (mostlythose that have nuclear-poweredairplane designed for towing con- takenplace over the past 5 or 6 years), andtun- ventionally powered airplanesduring long-range nel-wall-interferencepredictive methodsand mea- cruise, andan aerial transportationsystem corn surements.Future research requirements are prised ofcontinuously flying "liner" airplanes treated. operated in con junction with short-range "feeder" airplanes. The studiesindicate that each of *NASA, LangleyResearch Center, Hampton, Va. theseconcepts has the potential for important performanceand economic advantages, provided certainsuggested research tasks are successfully 75. *Eppler,Richard; and **Somers, Dan M.: -Low accomplished.Indicated research areas include Speed Airfoil Design andAnalysis. In the all-wingairplane aerodynamics, aerial rendezvous, "Advanced Technology Airfoil Research"conference, nuclearaircraft engines, air-cushion landing LangleyResearch Center, Mar. 7-9, 1978. NASA systems,and laminar flow control, as well as the CP2045,Vol. I, Part 1, March 1979,pp. 73-99. basicresearch discipline areas ofaerodynamics, structures,propulsion, avionics, andcomputer N79-20036# applications. A low speedairfoil design and analysispro- 'NASA, LangleyResearch Center, Hampton, Va. gram was developedwhich contains several unique features.In the design mode, thevelocity distribution is notspecified for one but many dif- 73.Advanced Technology AirfoilResearch. A con- ferentangles of attack.Several iteration ferenceheld at NASA, LangleyResearch Center, optionsare included whichallow the trailing edge Hampton, Va., March 7-9, 1978. angleto be specifiedwhile other parameters are NASA -2045,Vol. I. Pt. 1, Mar. 1979, 468pp. iterated. For airfoilanalysis, a panel method is N79-20030# available which usesthird-order panels having NASA CP2045,Vol. I. Pt. 2, Mar. 1979, 304 pp. parabolicvorticity distributions. The flow con- N79- 19989# dition is satisfied at the endpoints of the NASA CP2045, Vol. 11, Mar. 1979, 263 pp. panels. Both sharpand blunt trailing edges can N80-21283# be analyzed. The integral boundarylayer method with its laminarseparation bubble analog, empir- Thisconference provided a comprehensive ical transition criterion, andprecise turbulent reviewof all NASA airfoilresearch, conducted in- boundarylayer equations compares very favorably houseand under grant and contract. A broadspec- withother methods, both integral and finitedif- trum of airfoil research outside of NASA was also ference.Comparisons with experiment for several reviewed. The major thrust of thetechnical ses- airfoils over a verywide Reynolds number range sions were inthree areas: development of compu- are discussed.Applications to high lift airfoil tational aerodynamiccodes for airfoil analysis designare also demonstrated. anddesign, development of experimental facilities and test techniques, and alltypes of airfoil *Stuttgart Univ., West Germany applications.In addition, results of technical **NASA, LangleyResearch Center, Hampton, Va. workshopswere presented at aconcluding round- tablediscussion. 76. *Newman, Perry A.; and**Anderson, E. C.: Note:Selected papers from this conference AnalyticalDesign of a Contoured Wind-Tunnel Liner follow. forSupercritical Testing. In the "AdvancedTech- nologyAirfoil Research" conference held at LangleyResearch Center, March7-9, 1978, NASA 74. fBobbitt,Percy J. : LangleyAirfoil-Research CP2045,Vol. I, Pt. 2,March 1979,pp. 499-509. Program.In the "Advanced Technology Airfoil Research"conference held at LangleyResearch N79- 1999 3# Center, March 7-9, 1978, NASA CP2045,Vol. I, Part 1, March 1979,pp. 11-38. The presentanalytical design procedure is beingdeveloped in order to determinethe shape of N79-20032# a contourednonporous wind-tunnel liner for use in the Ames 12-footpressure wind tunnel test of An overviewof past, present, and future a large-chord,laminar flow control, swept-wing airfoil research activities at the Langley panel whichhas a supercritical airfoil section. ResearchCenter is given. The immediatepast and Thisprocedure is applicableto the two- future occupymost of thediscussion; however, dimensionalstreamlined tunnel problem and a first

18 f check on its validity wouldbe a comparisonof the 79.*Harvey, William D. : Influence ofFree-Stream F. calculatedtunnel-wall shape with that found Disturbances on Boundary-LayerTransition. NASA experimentally.Results for such a comparison are TM-78635, April1978, 33pp. givenand the favorable agreement is encouraging. N78-20460# *NASA, LangleyResearch Center, Hampton, Va. **DCW Industries,Inc., Studio City, Calif. Considerableexperimental evidence exists Contract NAS1-14517 which shows thatfree-stream disturbances (the ratio ofroot-mean-square pressure fluctuations to mean values)in conventional wind tunnelsincrease 77. *Meier, H. U.; and*Kreplin, H. P.: The withincreasing Mach number at low supersonic Influenceof Turbulent Velocity Fluctuations and to moderatehypersonic speeds. In addition to IntegralLength Scales of Low Speed Wind Tunnel localconditions, the free-stream disturbance Flow on the BoundaryLayer Development. AIAA levelinfluences transition behavior on simple 10thAerodynamic Testing Conference, San Diego, test models.Based on thisobservation, existing Calif., Apr. 19-21, 1978. InTechnical Papers noise-transitiondata obtained in the same test (A78-323261, 1978, pp.232-238. facility havebeen correlatedfor a large number ofreference sharp cones and flat plates and are AIAA-78-800 A78-32355# shown tocollapse along a singlecurve. This result is a significant improvementover previous The influence of the wind tunnelturbulence attemptsto correlate noise-transition data. on thedevelopment of a turbulent boundary was studied. The experiments were carriedout in the *NASA, LangleyResearch Center, Hampton, Va. Low Turbulence Wind Tunnelof the DFVLR-AVA at a free stream velocity of 20 m/s. The turbulence level (Tu( 1) approximatelyequal to 0.06%) was 80. *Newman, Perry A; and**Anderson, E. Clay: increased up to Tu( 1)approximately equal to 1% by NumericalDesign of Streamlined Tunnel Walls for a meansof variousgrids at differentpositions in %io-Dimensional Transonic %st. NASA “78641, thesettling chamber or nozzle. For a fixedtran- April 1978, 22 pp. sition and constantdistance from the nozzle throatthe effect of the wind tunnelturbulence on N78-23105# thewall shear stress was investigated.In particular it was triedto separate the effects which An analyticalprocedure is discussedfor result from theturbulence intensity andfrom the designing wall shapesfor streamlined nonporous turbulencestructure, which is differentin each two-dimensionaltransonic tunnels. It is based wind tunnel. upon currentlyavailable 2-D inviscidtransonic andboundary-layer analysis computer programs. *DeutscheForschungs- und Versuchsanstaltfuer Predictedwall shapes are comparedwith experi- Luft- und Raumfahrt. Institutfuer mentaldata obtained from the NASA Langley 6- by Stroemungsmechanik,Goettingen, West Germany 19-InchTransonic Tunnel where the slotted walls were replaced by flexible nonporouswalls. Com- parisonsare presented for the empty tunneloper- ating at a Mach number of 0.9 and for a supercritical test of an NACA 0012 airfoil at zero lift.Satisfactory agreement is obtainedbetween theanalytically andexperimentally determined wallshapes. (Such a liner will be requiredfor N78-20464# testing a large-cord, LFC, swept-wingpanel, which has a supercriticalairfoil section.) A compressibleNavier-Stokes solution procedure is appliedto the flow about an isolated *NASA, LangleyResearch Center, Hampton, Va. airfoil. Two majorproblem areas were investi- **DCW Industries,Inc., Studio City, Calif. gated. The firstarea is that ofdeveloping a Contract NAS1-14517 coordinatesystem andan initial step in this directionhas been taken. An airfoilcoordinate systemobtained from specification of discrete 81. *El-Hady, N. M.; and*Nayfeh, A. H.: Non- datapoints developed and the heat conduction parallel Stability of Two-Dimensional Heated equationhas been solved in this system. Efforts Boundary-LayerFlows, Proceedings of the 12th requiredto allow the Navier-Stokes equations to Symposium on NavalHydrodynamics, Wash., D.C., be solvedin this system are discussed. The June 5-9, 1975. secondproblem area is that ofobtaining flow fieldsolutions. Solutions for the flow about a The methodof multiplescales is used to circular cylinder and an isolated airfoil are pre- analyzethe linear, nonparallel stability of two- sented. In theformer case, the prediction is dimensionalheated liquid boundary layers. shown to be in good agreementwith data. Includedin the analysis are disturbances due to velocity,pressure, temperature, density and *UnitedTechnologies Research Center, East transportproperties with temperature. An equa- Hartford, Conn. tion is derivedfor the modulation of the wave Contract NAS1-13619 amplitudewith streamwise distance. Although the

19 analysis is applicable to bothuniform and non- andrelated groups of papers, primarily from the uniform wall heating,numerical results are pre- point of viewof the specialist in the given sub- sentedonly for the uniformheating case. The field. numericalresults are in good agreementwith the experimental results of Strazisar, Reshotkoand Prahl.

*VirginiaPolytechnic Institute and State Univer- 84. *Jernell,Lloyd S.: Effectsof Laminar Flow sity,Blacksburg, Va. Control on the Performanceof a Large- Span- Grant NSG- 1255 Distributed-Load Flying-Wing Cargo -Airplane- con- s.NASA 'IM-78715, June1978, 23pp.

82. flovell, W. A.; *Price, J. E.; *Quarterof N79-17851# C. B.; *Turriziani, R. V.; and *Washburn, G. F.: Design of a LargeSpan-Distributed Load Flying- The effects of laminarflow control (LFC)on Wing Cargo Airplanewith Laminar Flow Control. theperformance of a largespan-distributed-load NASA CR-145376, June 1978, 45 pp. flying-wingcargo airplane concept having a design payload of 2.669 MN andrange of 5.93 Mm were N78-30045# determined. Two configurations were considered. One employed laminarizedflow over the entire A designstudy was conducted to addlaminar surfaces of the wingand vertical tails, withthe flowcontrol to a previouslydesigned span- exception of theestimated areas of interference distributedload airplane while maintaining due to thefuselage and engines. The othercase constantrange and payload. Withlaminar flow differedonly in that laminar flow was notapplied controlapplied to 100 percentof the wingand to theflaps, elevons, spoilers, or rudders. The vertical tail chords,the empty weightincreased two cases are referredto as the 100 percent and by 4.2 percent,the drag 'decreased by 27.4 per- 80 percentlaminar configurations, respectively. cent,the required engine thrust decreased by The utilization oflaminar flow control results 14.8 percent,and the fuel consumption decreased inreductions in the standard day, sea level by21.8 percent. When laminarflow control was installed maximum static thrust per engine from appliedto a lesserextent of the chord (approxi- 240 kN forthe non-LFC configurationto 205 kN for mately 80 percent),the empty weightincreased by the 100 percentlaminar configuration and 209 kN 3.4 percent,the drag decreased by 20.0 percent, forthe 80 percentcase. Weight increases due to therequired engine thrust decreased by 13.0 per- the LFC systemscause increases in the operating cent, and the fuel consumptiondecreased by emptyweights of approximately 3 to 4 percent. 16.2 percent.In both cases the required take-off The designtakeoff gross weights decrease approxi- gross weightof the aircraft was less thanthe mately 3 to 5 percent. The FAR-25 takeofffield original turbulent aircraft. distancesfor the LFC configurations are greater by about 6 to 7 percent.Fuel efficiencies *Vought Corp., Hampton, Va. forthe respective configurations are increased Contract NAS1-13500 33 percent and 23 percent.

*NASA, LangleyResearch Center, Hampton, Va. 83.*Morkovin, M. V.: TechnicalEvaluation Report ofthe Fluid Dynamics Panel Symposium on Laminar- TurbulentTransition. Symposium heldat Lyngby, 85.*Nayfeh, A. H.; and*Padhye, A.: The Relation Denmark, May 2-4,1977; AGARD AdvisoryRept., BetweenTemporal and SpatialStability in Three- AGAFD-AR-122, 18 pp.,June 1978. (See citation DimensionalFlows. Presented atthe AIAA 11th nos. 36-43 forselected papers from this Fluidand Plasma Dynamics Conference,Seattle, symposium). Wash., July 10-12, 1978, 12 pp.

N78- 27882# AIAA-A78-45 78- 1 126 130

The AGARD Fluid Dynamics Panelorganized a An analysis is presented of thenonparallel three day symposiumon laminar-turbulenttransi- spatial or temporalstability ofthree-dimensional tionto review the progress achieved during the incompressible,isothermal boundary-layer flows last tenyears and to bring to light the still takinginto account the transverse velocity com- unsolvedproblems. There were a total oftwenty- ponentas well as the axial andcrossflow varia- ninepapers presented in five sessions. The list tions of the mean flow. The method of multiple of thesepapers heads the references at the end of scales is used to derive partial differential thereport. A secondsection of thisreport pre- equationsthat describe the axial andcrossflow sentsvarious considerations for evaluating theo- variations of thedisturbance amplitude, phase and retical andexperimental analyses of thetransi- wavenumbers.This equation is used toderive the tion phenomena withparticular concern to the expressionsthat relate the temporal and spatial improvement of methods forcalculating (transi- instabilities. mese relations are functionsof tion)onset anddevelopment on whichemphasis was the complexgroup velocities. Moreover, this focusedin the Call forPapers by the Program equation is usedto derive the expression that Committee. The subsequentsections then offer relatesthe spatial amplification in any direction evaluative comments concerningindividual papers to a calculatedamplification in any otherdirec-

20 1;'

tion.These relations are verified by numerical prop,advanced aerodynamics and active controls, resultsobtained for two- andthree-dimensional laminarflow control, and composites. disturbancesin two- andthree-dimensional flows. *NASA, Washington, D.C. *VirginiaPolytechnic Institute and State Univ., Blacksburg, Va. Grant NSG- 1255 89. *Leonard, R. W. : Airframesand Aerodynamics -

Aircraft Desigrin~"~. NASA Energy EfficientTransport program.Astronautics and Aeronautics, vol. 16, 86. *Kachanov, Yu. S.; *Kozlov, V. V.; and July-AUg., 1978, pp.38-46. *Levchenko, V. Ya.: Experiments on Nonlinear Interactionof Waves in BoundaryLayer. AIAA 11th A78-43359# Fluidand Plasma Dynamics Conference,Seattle, Wash., July 10-12, 1978, 12 pp. + 15 figures. The first part of thepaper discusses the Energy EfficientTransport program of theAircraft AIM-78- 1131 EnergyEfficiency (ACEE) program,giving attention to the developmentof active aerodynamics and The results of anexperimental study of the activecontrols. The secondpart of thepaper flow structure in a region of turbulent transition dealswith two otherportions of the ACEE program: obtained when initiating two harmonic waves being CompositePrimary Structures and Laminar Flow introducedinto the flat plate boundary layer are Control. described. The quasi-stationaryinterpretation of theobtained results is presented. On thebasis *NASA, LangleyResearch Center, Hampton, Va. of theobtained results and thepresented inter- pretation, some peculiarities of a "natural"transitionprocess are discussed. 90. *Gilbert, B.: Turbulent FlowsProduced by PerforatedPlate Generators in Wind Tunnels. *Institute of Theoretical andApplied Mechanics, Rept. no. LcGJ10987, Aug. 11, 1978, 18 pp. USSR Academy of Sciences,Novosibirsk. N79-29473# Note: Seepp. 135-144 in #139 inthis bibliography for asymposium paperwith the same title and An applicationof perforated sheet metal the same authors. plates was shown toprovide an efficient method of producing a largerange of turbulentflows forexperimental investigation. Fabrication of 87.*George-Falvy, D. : Summary Report of the a standarduniformly perforated grid was done Second Wind Tunnel Test of the Being LFC Model. quickly,with ordinary machine shop equipment. NASA CR-157792, Jiij-x, 1978, 27 pp. Differentflow geometries were producedaccurately withoutthe use of specialequipment. The stan- N79- 17799# dardgrid and two geometricvariations wereinves- tigatedgiving isotropic flow, wake flow,and uni- An 8-ftspan, 20-ft chord, 30 degswept wing formshear flow. Although the degree of isotropy sectionhaving provisions for laminar boundary was excellent,the variation in mean velocity controlover the first 30% of theupper surface profiles was slightlypoorer than found forother andthe first 15% of the lower surface was tested gridgenerators. The wake andshear flows were in a 5-ft by 8-ft wind tunnelto explore the comparable inquality to similar flows produced sensitivity of laminarflow to various forms of experimentally by other methods. disturbancessuch as surfaceimperfections, contamination,off-design pressure distribution *Grumman AerospaceCorp., Bethpage, N.Y. (increasedcrossflow), andimposed noise. The test equipmentused and instrumentation of the model aredescribed. Typical results obtained 91. *Fisher, David F.; and**Peterson, John B., from configurationswith spanwise ridges and span- Jr. : FlightExperience on the Need and Use of

wise rows of diskare discussed as well assuction Inflight-Lading. ~ Edge Washing for a Laminar Flow flow characteristics at reducedincidence. Airfoil.Presented at AIAA, Aircraft Systems andTechnology Conference, Los Angeles,Calif., *BoeingCommercial Airplane Co., Seattle, Wash. Aug. 21-24, 1978, 11 pp.

AIM-78-1512 A78-47947 88. *Kramer, J. J. : Planning a New Era in Air TransportEfficiency. Astronautics and Aeronaut- An investigation ofleading-edge contamina- ics, Vola 16,July-AUg. 1978, pp.26-28. tion by insects was conducted at the NASA Dryden FlightResearch Center with a JetStar airplane A78-43357# instrumented to detect transition on theoutboard leading-edgeflap and equipped with a system to The currentstatus of the NASA Aircraft wash theleading edge in flight. The results of Energy Efficiency (ACEE) program is briefly airline-typeflights with the JetStar indicated reviewedwith reference to CTOL aircraft. Atten- thatinsects cancontaminate the leading edge dur- tion is given to fourbasic technologies: turbo- ingtakeoff and climbout at large jet airports in

21 theUnited States. The results also showed that filamentary composite materials, induceddrag theinsects collected on theleading edges at improvements,propulsion, and the next generations 180 knots did not erode at cruiseconditions for a of transport aircraft. laminarflow control airplane and caused premature transitionof the laminar boundary layer. None of *Stanford Univ., Stanford, Calif. thesuperslick andhydrophobic surfaces tested showed anysignificant advantages in alleviating theinsect contamination problem. While there may 94.*Singh, P. ; *Sharma, V. P. ; and *Misra, u. N. : beother solutions to theinsect contamination ThreeDimensional Fluctuating Flow and Heat Trans- ~~~ ~ problem, theresults of these tests with a washer fer Along a Plate With Suction.Int. J. Heat and system showed that a continuous water spraywhile Mass Transfer, vol. 21, Aug. 1978, pp. 1117-1123. encounteringthe insects is effectivein prevent- inginsect contamination of the leading edges. A79- 18970

*NASA, Dryden FlightResearch Center, Edwards, The flowand heat transfer along a porous Calif. plate are investigated when a transversesinusoi- **NASA, LangleyResearch Center, Hampton, Va. dalsuction velocity distribution fluctuating with time is applied. Due to thistranverse velocity theflow of fluid is threedimensional. For 92. *Braslow, A. L.; and *Muraca, R. J.: A Per- asymptotic flowconditions, wall shear stress and spectiveof Laminar-Flow Control.Paper presented rate ofheat transfer are obtained. When fre- at AIAA Conferenceon Air Transportation: Tech- quencyparameter a + 0, it is foundthat the nicalPerspectives andForecasts, Los Angeles, phaselead of the skin friction in the cross-flow Calif., Aug. 21-24, 1978, 40 pp. direction is n/2.

AIAA-78- 1528 A78-46503# *IndiaInstitute ofTechnology, Kharagpur, India.

A historicalreview of thedevelopment of laminarflow control technology is presentedwith 95.*Nayfeh, A. FI.; and*Bozatli, A. N.: Second- ~ ~~~ reference to activelaminar boundary-layer control aryInstability in Boundary-Layer Flows-.VPI-E- throughsuction, the use of multiplesuction 78- 19, Aug., 1978,35 pp. (For a journal article slots, wind-tunnel tests, continuoussuction, and withthe same title see #129 in this spanwisecontamination. The ACEE laminarflow bibliography.) controlprogram is outlinednoting the development ofthree-dimensional boundary-layer codes, cruise- AbA058804 N79-13315# noiseprediction techniques, airfoil development, andleading-edge region cleaning. Attention is The stability of a secondaryTollmien- given to gloveflight tests and thefabrication Schlichting wave, whosewavenumber andfrequency and testing of wingbox designs. are nearlyone half of those of a fundamental Tollmien-Schlichtinginstability wave (T-S wave), *NASA, LangleyResearch Center, Hampton, Va. is analyzed by usingthe methodof multiples. Under theseconditions, the fundamental wave acts 93. fShevell, R. S.: The TechnologicalDevelop- as a parametric excitorfor the secondary wave. mentof Transport Aircraft - Pastand Future. When theamplitude of the fundamental wave is AIAA Conference on AirTransportation: Technical small, theamplitude of the secondary wave Perspectivesand Forecasts, Los Angeles,Calif., deviatesslowly from its unexcited state. How- Aug. 21-24, 1978, 19 pp. ever, as theamplitude of the fundamental wave increases, so doesthe amplitude of the secondary AIAA-78-1530 A78-46505# wave even inthe regions where it is damped in the unexcited state. The speedhistory of transport aircraft is examined. From 1928 to 1958 speedincreased five *VirginiaPolytechnic Institute and State Univ., fold. However, thebeginning of the jet age in Blacksburg, Va. 1958 establishedspeed levels whichhave shown Contract N00014-75-C-9381 little change inthe past 20 years. It is pointed outthat successful aircraft have almost always had equal or lower operating cost compared to 96. Ryzhenko, A. I.; andYasinskiy, F. G. : theirpredecessor while offering service improve- ProblemStatement in Planning and Analysis- of ment ineither speed, range comfort, or combina- Variantsof Mass-Production Designs of Bound- tionsof them. The technologicaldevelopment of aryLayer Suction Systems. NASA "-75269, thefuture is discussed,taking into account lam August1978. (U.S. Gov't. Agenciesand Their Con- inarflow control, nuclear powered aircraft,short tractors only. ) takeoffand landing aircraft, supersonic transports, hydrogen-fueledaircraft, prop-fan powered Translationof "Postanovka zadacha aircraft, andhypersonic transport. A description proyektirovaniya i analizavariantov seriynykh ofnear term technologicaladvances is also pre- knostruktsiy sistema otsosa pograniehnogosloya," sented.Attention is given to activecontrol Samoletostroyeniye - TekhnikaVozdushnogo Flota, technology,improved transonic airfoils, advanced NO. 40,1976, pp. 73-77.

22 X78-10024 (EnglishWanslation) 99.*Pope, G.:G. Prospectsfor Reducing the Fuel

A77-32713 (OriginalRussian) -~Consumption ~ ~ of Civil-iircraft. In: Energy and Aerospace;Proceedings of the ?mglo/American Con- Thispaper deals with the need to work out a ference, London, England, Dec. 5-7, 1978, set ofdesign solutions for boundary layer suction (A79-31908).Royal Aeron. SOC., 1979, 21 pp. (BLS) systems to minimizedrag on airframes,and topass the problem (achieve the milestone) of A79-31911 selecting the best variants ofsuch BLS systems for mass production, on thebasis of optimization An outline is providedof technological studies.Soviet andforeign work on optimization advancesthat will contributeto the reduction of ofthin-walled aviation structural elements and fuel consumption.Attention is concentrated applicableoptimization techniques are reviewed mainly on advancesbeing made inthe UK. The briefly.Boundary-layer laminarization, airframe emphasis is on developments that can be exploited skinfabrication variants, and tradeoffs in the in the generation of aircraft which will succeed designof BLS surface are discussed. the more recent of thetransport aircraft types now inservice andthose which will reachthe airlinesin the early 1980s. Advances in power- 97.*Gibson, J. S. : The Effects ofNoise on Lam- plants are examinedalong with developments in inar Flow Control DragReduction Systems. Pre- aerodynamics,taking into account advances in sented at 11thCongress of the International designtechniques, experimental facilities, wing Councilof the Aeronautical Sciences, Lisbon, tip design,drag reduction, and laminar flow con- Portugal,Sept. 10-16, 1978,Proceedings. Vol- trol.Attention is alsogiven to materials and ume 2, 1980,pp. 33-39, 24 refs. structures,active control technology, andopera- tionalconsiderations. A81-14390# *Royal AircraftEstablishment, Farnborough, Hants, The nature ofboundary layertransition from mgland laminar to turbulent flowand the problem of noise as a transition triggering mechanism are described. For historicalperspective, the noise 100. *Klineberg, J. M.: The NASA Aircraft Energy sourcesand laminar flow/noise criteria relative EfficiencyProgram. In: Energy and Aerospace: to the X-21A laminarflow control (LFC) research Proceedinss of the Anslo/ArnericanConference, " aircraft are reviewed. A more detailedreview is London, England, Dec. 5-7. 1978,(A79-31908). givenfor a passenger LFC transport aircraft, Royal Aero. Soc.,1979, 21 pp. which includesthe definition of noisesources, noisepredictions on aircraft LET surfaces, and A79-31912# criticallyaffected LFC areas. Currentactivities inthe area of noiseeffects on laminarflow are A review is providedof the goals, objec- brieflydiscussed, as are conclusions regarding tives, and recentprogress in each of six aircraft neededresearch. energyefficiency programs aimed at improvedpro- pulsive,aerodynamic and structural efficiency for 'Lockheed-Georgia Co., Marietta, a. futuretransport aircraft. Attention is given to engine component improvement,an energy efficient turbofanengine, advanced turboprops, revolution- 98. *Turriziani, R. V.; 'Lovell, W. A.; *Price, arygains in aerodynamic efficiency for aircraft J. E.: *Quartero, C. B.; and*Washburn, G. F.: of thelate 199Os, laminarflow control, and com-

~ Preliminary...... Design Characteristicsof a Subsonic posite primary aircraft structures. Business Jet ConceptEmploying Laminar Flow Con- __ "" ...... -trol. NASA CR-158958, Sept.1978, 40 pp. *NASAI Washington, D.C. N78-33087# 101. *BCAC PreliminaryDesign Dept.: Evaluation Aircraftconfigurations were developedwith ~ of Knar...... Flow Control System ConceptsSub- for LFC. laminarflow control (LFC) andwithout The __~sonic Commercial...... TransportAircraft, Final Rept., LFC configurationhad approximately eleven percent Sept. 1976 - Sept.1978. NASA CR-158976, less parasite drag and a seven percent increase in D6-47109, Dec. 1978, 269 pp. the maximum lift-to-dragratio. Although these aerodynamicadvantages were partially offset by N79- 15942# theadditional weight of the LFC system,the LFC aircraft burnedfrom six to eight percent less A two-yearstudy conducted to establish a fuelfor comparablemissions. For the trans- basisfor industry decisions on theapplication of atlanticdesign mission with the gross weight laminarflow control (LFC) tofuture commercial fixed,the LFC configuration would carry a greater transports was presented.Areas of investigation payload for ten percent fuel per passengermile. included: ( 1)mission definition and baseline selection: (2) conceptsevaluations; and (3) LFC 'Vought Corp., Hampton, Va. transportconfiguration selection andcomponent Contract NAS1-13500 design. The developmentand evaluation of com- petingdesign concepts was conductedin the areas ofaerodynamics, structures and materials, and

23 systems. The results of supporting wind tunnel exert a measurable influence on thedevelopment of and laboratory testing on a full-scale LEC wind turbulentboundary layers. panel,suction surface opening concepts and structural samples were included. A final LFC trans- *RoyalAircraft Establishment, Bedford, mgland port was configuredin incorporating the results ofconcept evaluation studies and potential performanceimprovements were assessed.Remaining 104. *Nayfeh, A. H.: Stability ofThree- problemstogether with recommendations for future DimensionalBoundary Layers. Presented at the research are discussed. 17thAerospace Sciences Meeting, New Orleans, La., Jan. 15-17, 1979, 10 pp. Also AIAA Journal, *BoeingCommercial Airplane Co., Seattle, Wash. vol. 18,no. 4, pp. 406-416,1980. Contract NAS1-14630 AIAA-79-0262 A79-23565#

102.*El-Hady, N. M.: Effect of Compressibility, A theory is developedfor the linear stabil- Suction,and Heat Transfer on theNonparallel ity of three-dimensionalgrowing boundary layers. Stability ofBoundary Layer Flows. VPI and SU The method of multiplescales is usedto derive Ph.D. Thesis,1978, 215 pp.(Available from Univ. partial-differentialequations describing the tem- Microfilms,Order no. 7921029.) poral and spatialevolution of the complexampli- tudesand wavenumbers of thedisturbances. In N79-32494 general,these equations are elliptic, unless certainconditions are satisfied. For monochro-a The effects ofheating, suction, and compres- maticdisturbance, these conditions demand that sibility on the stability characteristics of the ratio of the componentsof the complexgroup boundary layerflows within the frameworkof a velocity be real,thereby relating the direction completenonparallel, linear, spatial stability ofgrowth of the disturbance tothe disturbance theory was investigated.Included in the theory wave angle.For a nongrowingboundary layer,this aredisturbances due tovelocity, pressure, ten+ conditionreduces to da/df3 beingreal, where perature,density, and transport properties as a and f3 arethe complex wavenumbers inthe well as variations of thefluid properties with streamwise and crosswise directions,in agreement temperature. The methodof multiplescales is withthe result obtained by usingthe saddle-point usedto account for the nonparallelism of the mean method.For a wavepacket,these conditions demand flowand an equation is derivedfor the modulation thatthe componentsof the complexgroup velocity ofthe wave amplitudewith position. Stability be real. Inall cases, theevolution equations are characteristicsare examined for boundarylayer reducedto inhomogeneous ordinary-differential flowsover an adiabatic flat plate to study the equationsalong real groupvelocity directions. effect of a slightcompressibility of the mean flow. The feasibility of controlling boundary *VirginiaPolytechnic Institute and State Univ., layers by suctionthrough porous strips is inves- Blacksburg, Va. tigated and the results are compared withthe case Grant NSG- 1255 of continuousarea suction.

Dissertation Abstracts. 105. *Cebeci,Tuncer; and **Stewartson, Keith:

On Stability andTransition in -"Three-Dimensis *VirginiaPolytechnic Institute and State Univ., Flows.Presented at the AIh 17thAerospace Blacksburg, Va. SciencesMeeting, New Orleans, La., Jan. 15-17, 1979, 9 pp.Also AIAA Journal,vol. 18, April 1980, pp.398-405. 103. Weeks, D. J. ; and*Hodges, J. : An Drperi- mentalInvestigation into the Influence AIAA-79-0263 A79- 19630# ofAcoustic Disturbances on the Developmentof a TurbulentBoundary Layer. ARC-R/M-3825, BR64877, The usefulnessof the en method for pre- DCAF E010257, (supersedes RAE-TR-77035 and dicting transition in two-dimensionaland axially ARC-37524), 1978, 41 pp. symmetric flows is well established. In orderto extend the method tothree-dimensional parallel N79- 16238# shearflows, it is firstnecessary to establish a relationship between a and B, the complex wave The effects of acousticdisturbances on the numbers in two perpendiculardirections in the mean flow in a turbulent boundary layerdeveloping planeof flow. We suggestthat this may be done in a mildlyfavorable pressure gradient are dis- by makinguse of groupvelocity concepts which cussed. A Hartmann generator, mountedon the lead to therequirement aa/afl = -tan@,where @ centerline ofa transonic wind tunnel, was used is realand denotes the direction of propagation as a noisesource, and the mean flowin the bound- of centereddisturbances. As a paradigmof this arylayer on thetunnel sidewall was examined for approach,the rotating disk is studied. It is any effects of thenoise. It was notpossible to estahlishedthat the critical Reynolds number is identify any effect ofthe noise itself on the 176, thatthe principal disturbances to the lami- boundarylayer. It is concludedthat the acoustic narflow travel outwards and at an angle -8 deg disturbancesgenerally found in the working sec- to the direction ofmotion of the disk, while the tions of transonic wind tunnels are likely to appropriatevalue of n is -20. The observed

24 direction of propagation of disturbance is at of the amplification rates and the group veloci- -13 deg to the direction of motion of the disk. ties agree with existing results, obtained from The generally accepted value of n is -9, much incompressible theory. less than that found here. *Consultant, Iackheed-Georgia Co., Marietta, Ga. *California State Univ., Long Beach, Calif. Research supported by Lockheed-Georgia's IR and D **University College, London, mgland Program. ONR Contract N00014-76-C-0927

108. *Runyan, L. J.: and *George-Falvy, D.: 106. *Mack, L. M.: On the Stability of the Bound- Amplification Factors at Transition on an Unswept ary_lyer- on a Transonic Swept Wing. AIAA 17th Wing in Free Fliyht and on a Swept Wing in Wind Aerospace Sciences Meeting, New Orleans, La., Tunnel. Presented at AIAA 17th Aerospace Sciences Jan. 15-17, 1979, 17 pp. Meeting, New Orleans, La., Jan. 15-17, 1979, 18 PP- AIAA-79-0264 A79-23563# AIAA-79-0267 A79-23564# Both incompressible and compressible linear stability theory are applied to the three- Theoretically predicted amplification charac- dimensional compressible boundary layer on a par- teristics of Tollmien-Schlichting and crossflow ticular transonic sweptback wing of infinite span. disturbances are correlated with experimental data A spatial stability theory is used which identi- on transition location. A modified version of the fies the growth direction with the real part of MAM linear stability program was used to analyze the complex angle of the group velocity. It is two specific cases: an unswept sailplane wing of found that in the forward, but not the rear, high quality surface finish in free flight at low crossf low instability region, the maximum amplif i- Reynolds number, and a swept wing section in a low cation rates of the steady disturbances may be turbulence wind tunnel. For the sailplane wing, calculated to within about 10% by the incompres- where transition was caused by Tollmien- sible stability theory. !There is little differ- Schlichting type instability, the amplification ence between the sixth and eighth-order compres- factor corresponding to transition was found to be sible theories. The maximum amplification rate of about e to the 15th power. For the swept wing the steady disturbances at any chordwise station model, where transition was caused by crossflow is closely related to the maximum cross-flow at instability, the amplification factor correspond- that station independent of the Reynolds number. ing to transition was about e to the 12th power. For other than crossflow instability, there can be large differences between the incompressible and *Boeing Commercial Airplane Co., Seattle, Wash. compressihle theories, both as to the amplification rate and the angle of the wave-number vector for maximum instability. Amplitude ratios of 109. 'Boeing Preliminary Design Department: Eval- individual wave components are obtained by inte- uation of Laminar Flow Control System Concepts for grating the spatial amplification rate along the Subsonic Commercial Transport Aircraft, Summary growth direction subject to the constraint that Rept., Sept. 1976 - Sept. 1978. NASA CR-158998, the wavenumber vector is irrotational. This Jan. 1979, 79 pp. procedure yields steady disturbances aligned with the local potential flow direction whose wave- N79-21043# lengths are nearly independent of downstream distance. Results of a 2-year study are reported which were carried out to extend the development of 'California Inst. of Tech., Jet Propulsion Lab., laminar flow control (LFC) technology and evaluate Pasadena, Calif. LFC systems concepts. The overall objective of Contract NAS7- 100 the LFC program is to provide a sound basis for industry decisions on the application of LFC to future commercial transports. The study was orga- 107. *Lekoudis, Spyridon G.: Stability of Three- nized into major tasks to support the stated Dimensional Compressible Boundary Layers over objectives through application of LFC systems con- Wings with Suction. Presented at AIAA 17th Aero- cepts to a baseline LFC transport initially gener- space Sciences Meeting, New Orleans, La., ated for the study. Based on competitive evalua- Jan. 15-17, 1979, 12 pp. tion of these concepts, a final selection was made for incorporation into the final design of an LFC AIM-79-0265 1# 1963 A79- transport which also included other advanced technology elements appropriate to the 1990 time The problem of the propagation of three- period. dimensional laminar instabilities in a three- dimensional compressible boundary layer is exam- *Boeing Commercial Airplane CO., Seattle, Wash. ined using linear stability theory. The theory is Contract NASI- 14630 applied to the case of a swept wing with suction. Compressibility is stabilizing especially when the disturbance is of the Tollmien-Schlichtinq type. 110. *Boeinq Preliminary Design Dept.: Aircraft When compressibility is .neglected the calculations Surface Coatings Study: Energy Efficient Trans-

25 port Program - Sprayedand Adhesive Bonded Coat- (6 X 9in. ) demonstrationpanels. Included were ingsfor DragReduction. Final Rept., %-46699, bothsandwich and stiffened semi-sandwich panels NASA CR-158954, Jan.1979, 115pp. with slotted and perforated surfaces.

N81-12225# Subsequent to the evaluation of thethree demonstrationpanels, one concept was selectedfor Surfacecoating materials for application fabrication of a 0.3 X 1.0 meter ( 12 X 42inch) on transporttype aircraft to reduce drag, were feasibilitypanel. It was a stiffened, semi- investigated. The investigationincluded two sandwichpanel with a slotted surface, designed to basic types of materials: spray on coatingsand meet therequirements of theupper wing cover at adhesively bonded films. A cost/benefitsanalysis the maximum wingbending moment ofthe baseline was performed,and recommendations were made for configuration. future work towardthe application of this technology. 'Rockwell International, Los Angeles,Calif. Contract NAS1-14566 *BoeingCommercial Airplane Co., Seattle, Wash. NASI- 14742 114.*Wright, Andrew s.: Aircraft hergy Effi- ciencyLaminar Flow ControlGlove Fligh-t Concep- 11 1. *Keefe,Laurence R. : A Studyof Acoustical tual DesignStudy. NASA TM-80054, Jan.1979, 34 Fluctuationsin the Langley 8-Foot Transonic Pres- * ~ ~ PP sureTunnel. NASA CR-158983 Jan.1979, 29 pp. (U.S. Gov't.and Their Contractors(xlly.) N79-20100#

X79- 10022# A conceptualdesign study of a laminarflow controlglove applied to the wingof a short to *Wyle Labs,Inc., Hampton, Va. medium range jet transportwith aft mounted NASA G67019-A engineshas been completed. Two suctionsurfaces were studied--aslotted aluminum gloveconcept and a woven stainless steel mesh porousglove concept.

112. *Baraer.-. Ravmond - L.: A TheoreticalInves- ~ ~~ The laminarflow control glove and a dummy glove tigation ofForebody Shapes Designed forNatural with a modifiedsupercritical airfoil, ducting, ~~ ~. LaminarBoundary-Layer Flow. NASA TP1375, modifiedwing leading and trailing edges, modified flapsand an LFC trim tab were applied to the wing after slot spacingsuction parameters, and com- N79- 15903# pression power were deterrdned. The results of thestudy show that a laminarflow control glove The design offorebody shapes for natural can be applied to the wingof a jet transportwith laminarflow is discussed.For subsonic flow, an appropriatesuction system installed. computed resultsfor three shapes of different finenessratios indicate that laminar flow can be *NASA, LangleyResearch Center, Hampton, Va. attainedunder conditions that approximate those on theforebody of acruise missile flying at a low altitudeat a high subsonic Mach number. For 115. *Turriziani, R. V.; *Lovell, W. A.; *Price, supersonic (Mach 2.00) design,a one-parameter J. E.; *Quartero, C. B.; and*Washburn, G. F.: familyof hyperbolic arcs was usedto generate Evaluation ofa Long-Endurance-Surveillance forebodyshapes having a favorablepressure grad- Remotely-PilotedVehicle With andWithout Laminar ientover the forebody length. Computed results Flow Control. NASA CR-159006, Feb. 1979, 56 pp. forthese shapes indicated laminar and transi- tionalflow over the range ofReynolds numbers N79- 17852# considered. Two aircraft were evaluated,using a derated *NASA, LangleyResearch Center, Hampton, Va. TF34-GE-100 turbofanengine one with laminar flow control (LFC) andone without. The missionof theremotely piloted vehicles (RPV) is oneof 113. *McQuilkin, F. T.: Studyof the Application high-altitude loiter at maximum endurance. With ofSuperplastically Formed andDiffusion Bonded the LFC system maximum mission time increased by (SPF/DB) TitaniumStructure to Laminar Flow Con- 6.7 percent, L/D inthe loiter phaseimproved trol (LFC) Wing Design. NASA CR-158979, 14.2 percent,and the minimum parasite drag of the Jan.1979, 101 pp. wing was reduced by 65 percent resulting in a 37 percentreduction for the total airplane. N79-20070 Exceptfor the minimum parasite drag of the wing, the preceding benefits include the offsetting Eighteendesign concepts for a LFC wing effects of weightincrease, suction power require- cover,using various SPF/DB approaches,were ments,and drag of the wing-mounted suction pods. developed.After evaluation of producibility, In a supplementarystudy using a scaled-down, compatibilitywith LFC requirements,structural ratherthan derated, version of theengine, on the efficiency and fatiguerequirements, three candi- LFC configuration,a 17.6 percentincrease in mis- dates were selectedfor fabrication of 15 x 23 cm

26 9 sion time over theairplane without LFC andan (N79-23889#),pp. 81-82, held at NASA, langley =d incremental time increaseof 10.2 percentover the ResearchCenter, Hampton,Va., March 29-30, 1979. 7' LFC airplanewith derated engine were attained. Thisimprovement was due principally to reductions N79-23893# in bothweight and drag of the scaled engine. Disturbancessuch as flap and aileronhinges *Vought Corp., Hampton, Va. andpoorly faired spoilers were simulatedin a Contract NAS1-13500 computer wind tunnel. The total drag of asingle roughnesselement does not depend only on the size of thatelement. Its position on the wing 116.*Mangiarotty, R. A.; and *Bohn, A. J.: Wind hasa surprisingly strong effect. In particular, TunnelStudy on theEffects of Acoustical Dis- a roughnesselement on the convex side of a turbances on ControlledLaminar Flow. AIAA 5th deflected flap or aileron causes a verysubstan- AeroacousticalConference, Seattle, Wash., tial increasein drag. Very few experimentaldata March12-14, 1979, 11pp. are availablefor comparison. Good agreementwith experimentcan be achieved, however, by adapting a AIAA-79-0629 A79-26922# fictive"step size." The correlation between the real roughness-elementsize and the drag increase An exploratorystudy was conducted to inves- remainsto be determined.Simple, fundamental tigate the sensitivity oflaminar flow controlled experiments are suggested which will allow a theo- (LFC) boundary layers to externalacoustical dis- reticalestimation of the dragincrease due to turbancesusing an &ft span, 20-ft chord, and roughnesselements. 30-deg sweptwing sectionwith laminar flow control throughspanwise slots. The objectives were *Stuttgart Univ., Stuttgart, West Germany toidentify Tollmien-Schlichting and other ampli- ficationfrequencies, critical disturbancelevels inthe boundary layer,the influence of suction 119. *Eppler, R.: Some New Airfoils. The Science rate on thesedisturbances, and thetransfer func- andTechnology of Low Speedand Motorless Flight, tion betweenan external sound field and the cor- NASA CP2085,Pt. 1 (N79-23889#),pp. 131-154, respondingdisturbance induced in the boundary heldat NASA, LangleyResearch Center, Hampton, layer. Va., March 29-30, 1979.

*BoeingCommercial Airplane Co., Seattle, Wash. N79- 23896# Contract NASI- 14630 A computerapproach tothe design andanalysis of airfoils and some common problemsconcern- 117.*Eggleston, B.; *Jones, D. J.; and inglaminar separation bubbles at different lift **Elfstrom, G. M.: Developmentof Modern Air- coefficientsare discussed briefly. Examplesof foilSections for High SubsonicCruise Speeds. applicationto ultralight airplanes, canards, and In: AIAA TechnicalPapers (A79-27351,pp. 9-16) sailplaneswith flaps are given. ofAtlantic Aeronautical Conference, Williamsburg, Va., Mar. 26-2Ef 1979, 8 pp. *Stuttgart Univ., Stuttgart, West Germany

AIAA-79-0687 A79-27353# 120. *Blackwelder, R. F.: BoundaryLayer han- Some recent Canadian work on thedesign and sition.Physics of Fluids,vol. 22, no. 3, test of airfoilsfor high subsonic aircraft is March 1979,pp. 583 and 584. reviewed.Comparisons of theory and experiment are presentedfor two16% thickairfoils. (Xle A79-28324 airfoil was designedusing numerical optimization while the other was designed by inverse methods It is suggestedthat boundarylayer transi- withrefinements to improveperformance. The tion on a flat plate my be consideredas a cas- inversedesign airfoil inproved maximum lift coef- cadeof at least three distinct instabilities. The ficients 20% at all Mach numbers tested (0-2-0.80) oscillationfrequency of thevelocity "spike" is anddemonstrated that a concavepressure recovery predicted by the growthof a localizedfree shear was notdetrimental. Anticipated improvements due layer that is a result of the earlier to naturallaminar flow were notrealized at high instabilities. subsonic Mach numbersand high Reynolds numbers (20 x 106). 'Dept.of AerospaceEngineering, Univ.of Southern Calif., Los Angeles,Calif. *deHavilland Aircraft of Canada, Ltd., Downsview, Researchsupported by the Guggenheim Foundation Ontario, Canada andMax-Planck-Institut fuer Stroemungsforschung. **NationalResearch Council, Mtawa, Canada

121. *Roache, P. J.: SemidirectComputation of 118. *Eppler, R.: The Effectof Disturbances on Three-DimensionalViscous Flows Over SuctionHoles a Winq. The Scienceand Technology of Low Speed in Laminar Flow ControlSurfaces. Final Report. andMotorless Flight, NASA CP2085,Part I NASA CR-159017f March 1979, 23 pp.

27 N79-21005# Some of these include a conventionalaircraft capableof carrying a 400,000-lbload over a range A summary is givenof the attempts made to of 6200 n.mi., a laminarflow control aircraft, applysemidirect methods to the calculation of where slotted wingand tail surfacesprovide lami- three-dimensionalviscous flows over suction holes narflow to 70% chord to conservefuel, nuclear- in laminarflow control surfaces. The attempts powered aircraftwith active-controls technology, were allunsuccessful, due toeither (1) lack of swept-wing space-distributed-load aircraft capable resolutioncapability, (2) lack ofcomputer effi- of carrying a million pounds ofpayload, wing-in- ciency, or (3)instability. ground-effectvehicles, a power-augmented-ram/ wing-in-ground-effectvehicle, and the heavy-lift *EcodynamicsResearch Associates, Inc., airship. Albuquerque, N. Mex. Contract NASI- 15045 *AeronauticalSystems Div., Wright-Patterson AFB, Ohio **Flight Dynamics Lab.,Wright-Patterson AE'B, Ohio 122. *Nayfeh, Ali H.: Effect of Streamwise Vortices on Tollmien-Schlichting Waves. NASA CR-162654;VPI-E-79-12; March 1979, 20 pp. 125. *Meade, L. E.: Fabrication ofThick Graphite/Epoxy Wing SurfaceStructure for @- N80- 16294# sonicTransport Aircraft. In: "Enigma of t Eighties:Environment, Economics, Energy." SOC. The methodof multiple scales is used to for the Advancement ofMaterial and Process Engi- determine a firstorder uniform expansion for the neering,24th National Symposium andExhibition, effect of counterrotating steady streamwise vor- San nancisco,Calif., May 8-10, 1979, tices in growingboundary layers on Tollmien- Book I, (A79-432281, pp. 252-259. Schlichting waves. The results show thatsuch vorticeshave a strongtendency to amplify three A79-43245 dimensionalTollmien-Schlichting waves having a spanwisewavelength that is twicethe Wavelength The fabrication of thickstructural laminates of thevortices. An analyticalexpression is from Narmco 5208/T300 graphite/epoxyprepreg has derived for the growth rates of these waves. presentedproblems of dimensional and void content These growth rates increaselinearly with increas- control. This paperdescribes the fabrication ingamplitudes of the vortices. processdevelopment conducted on Laminar Flow Con- trol wing surfaces for passengertransport appli- *VirginiaPolytechnic Institute and State Univ., cationsto achieve thick laminates of highqual- Blacksburg, Va. ity. The stepsaddressed include prebleeding, Contract N00014-75-C-03811 layup,tooling aids, and curing to achieve the Grant NsG- 1255 requiredlaminate quality.

*Lockheed-Georgia Co., Marietta, Ga. 123. *Arata, W. H., Jr.: Very LargeVehicles, AircraftDesign Concepts. Astronautics and Aero- nautics,vol. 17, April 1979,pp. 20-25, 33. 126.*Molloy, J. K. : Advanced Air Transport Con- cepts - Reviewof DesignMethods for Very Large A79- 30484# Aircraft. AIAA StudentJournal, vol. 17, Spring 1979,pp. 12-16. Some of theconcepts being studied for large aircraft are brieflydiscussed. Concepts for A79-31121# conventionaltakeoff and landing aircraft, distributed-loadaircraft, wing-in-ground effect The conceptsof laminar flow control, very aircraft,multiple fuselages, the laminar-flow largeall-wing aircraft, an aerial relay transpor- controlaircraft, nuclear powered tug,air- tationsystem and alternative fuels, whichwould cushion-landing-systemaircraft, blimp-helicopter enablelarge improvements infuel conservation in combination,and surface-effect ships are men- airtransportation in the 1990'sare discussed. tioned. Laminarboundary layercontrol through suction would greatlyreduce skin friction andhas been *NorthropCorp., IDS Angeles,Calif. reportedto reduce fuel consumption by up to 29%. Distributedload aircraft, in which all fueland payload are carried in the wingand thefuselage 124. *Noggle, L. W.; and**Jobe, C. E.: Large- is absent,permit the use of lighter construction VehicleConcepts - AircraftDesign. Astronautics materialsand the elimination of fuselage and tail andAeronautics, vol. 17, April 1979, pp. 26-32. drag.Spanloader aircraft with laminar flow control could be used in an aerial relay transporta- A79-30485# tionsystem which would employ a networkof con- tinuouslyflying liners supplied with fuel, cargo The paperbriefly surveys mostof thevery and crews by smaller feederaircraft. Liquid largevehicle concepts examined by Air Force, hydrogenand methane fuelsderived from coal are Navy, NASA, andindustry in recent study efforts.

28 t"

shown to be wre weightefficient and less costly 129.*Nayfeh, A. H. ; and*Bozatli, A. N. : Sec- d." thancoal-derived synthetic jet fuels. ondaryInstability in Boundary-LayerFlows. >'.L~ Physicsof Fluids, Vol. 22, May 1979,pp. 805-813. *NASA, LangleyResearch Center, Hampton, Va. (Fora report with the same title see #95 in this bibliography.)

127. *BoeingPreliminary Design Department: A79- AD-A074792 3640 1 Natural Laminar Flow AirfoilAnalysis and Trade Studies,Final Rept. Aug. 1977 - June 1978. The stability of a secondaryTollmien- NASA CR-159029, May 1979,84 pp. Schlichting wave,whose wavenumber andfrequency arenearly one halfthose of a fundamental N82- 15018# Tollmien-Schlichtinginstability wave, is analyzed usingthe method of multiplescales. Under these Recentdevelopment of advanced computer tech- conditions,the fundamental wave acts as apara- niquesfor boundary layer analyses and airfoil metric exciterfor the secondary wave. The design,and advances in manufacturing methods for results show thatthe amplitude of thefundamental low-cost,smooth-surfaced bonded structure have wave must exceeda critical value to trigger this combined toprovide new interest in natural lami- parametricinstability. This value is propor- narflow technology. tionalto a detuning parameter which is the real part ofk - 2K, whereandk K are the wave- This document constitutes the final report of numbers of thefundamental and its subharmonic, two of thesubtasks, of Contract NASl-14742. The respectively. For theBlasius flow, the critical first subtask was to define an airfoil for a large amplitude is approximately 29% ofthe mean flow, commercial transportcruising at Mach 0.8. The andhence many othersecondary instabilities take secondsubtask was to incorporate the airfoil into placebefore this parametric instability becomes a naturallaminar flow transport configuration and significant. For otherflows where the detuning compare fuelrequirements and operating costs to parameter is small,such as free-shearlayer those of anequivalent turbulent flow transport. flows,the critical amplitude can be small; thus the parametric instability mightplay a greater A thirdsubtask was pursuedas a separate role. studyand is reportedin NASA CR-158954, "Aircraft SurfaceCoatings Study," which is no. 110 in this *VirginiaPolytechnic Inst. and State Univ., compilation. Blacksburg, Va. Grant NSG- 1255 'BoeingCommercial Airplane Co., Seattle, Wash. Contract NAS1- 14742 130. Vousteix, J.; and 'Pailhas, G.: Exploratory Studyof a Laminar-Turbulent Transition Process 128. *Anderson, E. C.: User Guide for STRMLN: A Near thePoint ofLaminar Boundary Layer Separa- Boundary-LayerProgram for Contoured Wind-Tunnel tion. ONERA TP-1979-86. June1979. La Rgcherche Liner Design. FinalReport. NASA CR-159058; Aerospatiale, May-June 1979, pp.213-218. (In DCW-R-15-02:May 1979, 52 pp. French. )

N79-23114# A79-41308#

A 2-D boundary layer computercode developed The point andnature of laminar-turbulent toprocess data for an arbitrary number of stream- transition was studiedsystematically in asmall lines is presented.Provisions are included for subsonic wind tunnel,using models with various the computercode to determineeither mass trans- angles of sweepand a wide range of angles of ferrates necessary for an effective boundary attack. The technique employed was based on sub- layerdisplacement of zerothickness or theeffec- limitation ofacenaphtene coatings and on hot-wire tivedisplacement thickness for a specified mass anemometer probingsof the boundary layer. Tran- transfer-ratedistribution. The computercode was sition was found to be a phenomenonwhose charac- developed to be compatiblewith other computer teristics are strongly influenced by such param- codeswhich arebeing modified and/or developed at eters asthe pressure gradient. Further studies the NASA-Langley ResearchCenter in order to of the transition phenomenon are in progress. design the threedimensional, contoured, wind tunnelliner used in transonic testing of a lami- 'ONERA, Centred'Etudes et de&cherches de narflow control system installed on a super- Toulouse,Toulouse, France criticalairfoil section. A briefdescription of theliner design procedure, representative liner calculations,adaptive-wall design for a two 131.*Hefner, Jerry N.; and'Bushnell, dimensional wind tunnel test, and otherapplica- Dennis M.: Application- of Stability Theory tionsare reported. to Laminar Flow Control.Presented at the AIAA 12thFluid and Plasma Dynamics Conference, 'Dow Industries,Studio City, Calif. Williamsburg, Va., ;luly 23-25, 1979, 20 pp. Contract NASI- 14517 AIAA-79- 1493 A79-4669 1X

29 The papersummarizes the state-of-the-art for When crossflowdisturbances were computed using application of stability theory to laminarflow spatialtheory and for a limitedrange of angles controlusing suction, wall temperatureand/or ofwavegrowth direction,the growth rate inthe favorable pressure gradient ( "natural laminar direction formed by the real ratio of thegroup flow").Discussions include current LFC problem velocities and the direction itself were insensi- areas requiringstability analyses, methodsof tiveto the orientation of the wave growth. When relating stability theory to transition with temporaltheory was used,this condition resulted results from dataand theory comparisons available in a single wave of maximum amplification. It is thusfar, and a summary of low disturbancedata found that wall cooling has a stabilizing effect availablefor theory calibration on sweptwings. on crossflowdisturbances, but the stabilization Criticalissues highlighted are problemspeculiar is mildcompared to the stabilizing effect that to suction LFC on highperformance transonic wings wall cooling has on Tollmien-Schlichtingwaves. andapplication of theeto-the-n-power method to both low andhigh speed flight data. 'Lockheed-Georgia CO., Marietta, Ga. Researchsupported by Lockheed-Georgia's IR&D *NASA, LangleyResearch Center, Hampton, Va. Program.

132. *Nayfeh, A. H.; and *El-Hady, N. M.: 134.*Nayfeh, A. H. ; and**Bozatli, A. N. : hraluation of Suction ThroughPorous Stripsfor Nonlinear Wave Interactionsin BoundaryLayers. Laminar Flow Control. AIAA 12thFluid and Plasma Presentedat AIAA 12thFluid and Plasma Dynamics Dynamics Conference,Williamsburg, Va., July 23- Conference,Williamsburg, Va., July 23-25, 1979, 25,1979, 14 pp. 18 PP.

AIAA-79- 1494 AIAA-79- 1496

An evaluation is presented of suctionthrough A model is proposedfor the excitation of porousstrips for laminar flow control. The three-dimensional waves intwo-dimensional linearstability theory and theexp(N) criterion boundary-layerflows. me model is aninteraction are used toinvestigate the case of suction of four waves:two two-dimensional waves having throughporous strips and compare it withthe case thefrequencies w and 2w and two three- of continuousarea suction. A numberof calcula- dimensional waves havingthe frequency w. Numer- tions havebeen performed for strips of various icalresults for nonparallel spatially growing widthsand spacings subject to the constraint waves are obtainedfor the experimental conditions of constanttotal mass flowthrough the strips. ofKlebanoff , Tidstrom,and Sargent. The results The amount of suctionrequired to keep the factor show thatthe proposed model is capable of predic- N below some semi-empiricalvalue is determined. ting the growthof thethree-dimensional waves. The effect of suctionthrough a strip is not limitedto the region over the strip but extends *VirginiaPolytechnic Institute and State Univ., bothupstream (upstream influence) and downstream Blacksburg, Va. (downstreaminfluence). The effectiveness of a **Univ.of Arkansas, Fayetteville,Arkansas strip can be increasedconsiderably by increasing ONR Contract NO00 14-75-C-0381 and NASA Grant theextent of theupstream influence (sink NSG- 1255 effect). The results show thatthe number of strips and theirwidths and spacings can be optimized so thatthe total suction levels needed are 135.*Floryan, Jerzy M.; and*Saric, William S.: about 5- 10% larger than those needed to achieve Stability of GGrtler Vorticesin BoundaryLayers the same stabilitycharacteristics using continu- WithSuction. AIAA 12thFluid and Plasma Dynamics ousarea suction. Conference,Williamsburg, Va., July 23-25, 1979, 18pp. AIAA Journal,vol. 20, March 1982, *VirginiaPolytechnic Institute and State Univer- pp. 316-324. sity,Blacksburg, Va. Grant NSG- 1255 AIAA- 79- 1497 A82-23830#

The formalanalysis of GErtler-type instabil- 133. *Lekoudis,Spyridon G. : The Stability of the ity is presented. The boundary-layerand the Boundary Layer on aSwept Wing With WallCooling. disturbanceequations are formulated in a general, Presentedat AIAA 12thFluid and Plasma Dynamics orthogonal,curvilinear system of coordinates Conference, July 23-25 , 1979, Williamsburg, Va. , constructed from theinviscid flow over a curved 10 PP. surface.Effects of curvature on the boundary- layerflow are analyzed. The basicapproximation AIAA-79- 1495 A79-46692# forthe disturbance equations is presented and solvednumerically. Previous analyses are dis- Linearstability theory is used to examine cussedand compared with our analysis. Effects of thepropagation of laminarinstabilities in the suction are introducedand discussed, and the leadingedge region of a transonicswept wing with results show that the stability characteristics wallcooling. Before this could be done, the dependon thenormal-velocity terms. Stabiliza- effects ofcomputing real groupvelocity ratios tion due to suction is notnoticeable until the for monochromatic waves needed investigation. suctionexceeds a certaincritical value. It is

30 ,- ..,.

found that large suction is requiredfor the 138. *Tibbetts, J. G.: Near-Field Noise Predic- stabilization of the boundary layerover a curved tion For Aircraftin Cruising Flight: Methods -.., surf ace. .Manual-Laminar. .- .. . Flow Control Noise Effects Analysis.Final Report, May 1977-June1978. *VirginiaPolytechnic and State Univ.,Blacksburg, LG78ER0219; NASA -159105, Aug. 1979, 97 pp- Va . Grant NSG- 1255 N80- 128 19#

Methods for predicting noise at any point on 136. *Owen,F. K. ; **Stainback, P. C. ; and an aircraft while the aircraft is ina cruise **Harvey, W. D.: Evaluationof Flow Qualityin flight regime are presented.Developed for use in Two NASA Transonic Wind Tunnels. AIAA 12thFluid laminarflow control (LFC) noiseeffects analyses, andPlasma Dynamics Conf ., Williamsburg, Va., theycan be used in any case where aircraftgener- July 23-25, 1979, 11 pp. atednoise needs to be evaluated at a location on an aircraftwhile under high altitude, high speed AIAA-79-1532 A79-46714# conditions.For each noise source applicable to the LFC problem, a noisecomputational procedure Testshave been conducted in the Langley is givenin algorithm format, suitable for comput- ResearchCenter &.Foot Transonic Pressure Tunnel erization.Three categories of noisesources are and the Ames ResearchCenter 12-Foot Pressure Wind covered: (1) propulsionsystem, (2) airframe, and Tunnel in order to measure characteristic distur- (3) LFC suctionsystem. In addition, procedures bance levels andenergy spectra in their respec- are givenfor noise modifications due to source tivesettling chambers, test sections, and soundproofingand the shielding effects of the diffusersand to determine the sources of these aircraftstructure whereverneeded. Sample cases, disturbances.Results are presented and discussed for each of theindividual noise source proce- alongwith some specific recommendations. dures,are provided to familiarize the user with typicalinput andcomputed data. 'Complere Inc.,Palo Alto, Calif. **NASA LangleyResearch Center, Hampton, Va. *Lockheed-Georgia CO., Marietta, Ga. Contracts NAS1-14833 and NASI-15223. Contract NAS1-14946.

137. *Swift, G.; and 'Mungur,P.: A Studyof the 139.*Eppler, R.; and'Fasel, H., Editors: Prediction of CruiseNoise and Laminar Flow Con- ~~ ".Laminar-Turbulent .~ Transition, Sept. 16-22, 1979. trol~Noise Criteria ForSubsonic Air Transports, Proceedings of the Symposium sponsored by IUTAM, FinalRept., May 1977-June 1978; LG78ER0218; DFG, Universitat,Stuttgart, et al.Berlin, NASA CR-159104, AUg. 1979, 262 pp. Springer-Verlag,1980, 451 pp., 34 papers.

N80-12818# A81-18101

Generalprocedures for theprediction of com- The studiescontained in this volume provide ponentnoise levels incident upon airframesur- anoverview of the current research in the field facesduring cruise are developed. Contributing of hydrodynamic stability and transition to tur- noisesources are those associated with the pro- bulence.Papers are presented on thelocal cri- pulsionsystem, the airframe and the laminar flow teria of hydrodynamic stability,the transition control (LFC) system.Transformation procedures mechanicsof an oscillating boundary layer,three- from thebest prediction base ofeach noise source dimensional waves ina boundary layer, and the tothe transonic cruise condition are estab- generation of aTollmien-Schlichting waveby a lished. Two approachesto LFC/acoustic criteria sound wave. Otherstudies include the laminar- are developed. The first is a semi-empirical turbulenttransition in Taylor-Couette flow, a extension of the X-21 LFC/acoustic criteria to visualstudy of the growthand entrainment of includesensitivity to the spectrum and direction- turbulent spots, andnumerical studies of transi- ality of the sound field. In thesecond, the more tionin planar shear flows. fundamentalproblem of how sound excites boundary layerdisturbances is analyzed by deriving and fstuttgartUniversitat, Stuttgart, West Germany solvingan inhomogeneousOrr-Sommerfeld equation in which thesource terms are proportional to the productionand dissipation ofsound induced fluc- 140.*Nayfeh, A. H.: Three-Dimensional Stability tuatingvorticity. Numerical solutions are of Growing BoundaryLayers. Proceedings of the obtainedand compared withcorresponding measure- International Union of Theoretical andApplied ments.Recommendations are made to improveand Mechanics Symposium on Laminar-TurbulentTransi- validateboth the cruise noise prediction methods tion,held at Stuttgart, Germany, Sept. 16-22. and theLFC/acoustic criteria. 1979,(~81-18101, pp. 201-217), Springer-Verlag, 1980. *Lockheed-Georgia Co., Marietta, Ga. Contract NAS1- 14946 A81-18117

31 A theory is developedfor the linear stabil- positionednormal to the mean flowin the settl- ity of three-dimensionalgrowing boundary layers. ing chamber. However, this is true only when a The method of multiple scales is used to derive 45deg-screen is mountedinmediately downstream partial-differentialequations describing the of the honeycomb, and when some distance is temporal and spatial evolution of the complex providedbetween the trailing edges of the corner amplitudesand wavenumbers of thedisturbances. turningvanes and the upstream side of the 45 deg- Ingeneral, these equations are elliptic unless honeycomb. This distance is required for adequate certainconditions are satisfied.For a mono- decay of theturning-vane wakes, therebyproviding chromaticdisturbance, these conditions demand a reasonablyuniform mean flowentering the honey- that the ratio of the components of the complex comb. Results demonstratethat this distance groupvelocity be real andthereby relate the should be at least twicethe spacing between the direction of growthof the disturbance to the turningvanes. Even thoughthe resulting turbu- disturbance wave angle.For a nongrowing bound- lenceintensity is the same downstream of both ary layer,this condition reduces to da/df3 the 45 deg-honeycomb andthe conventional honey- being real, inagreement with the resultobtained comb, there wouldhave to be a significant by usingthe saddle-point method.For wave-a improvement in the test-sectionturbulence inten- packet,these conditions demand thatthe compo- sity,using the 45deg-honeycomb to justify the nentsof the group velocity be real. additionalexpense in fabricating and installing thistype of honeycomb. *VirginiaPolytechnic Institute and State Univ., Blacksburg, Va. *IllinoisInst. of Tech., Chicago, Ill. GrantNSG1255 (Navy supportedresearch.) Grant NSG- 145 1

141. *Bushnell,Dennis M.; and**Tuttle, Marie H.: 143. *Hough, G. R. (ea.): Viscous Flow Drag Surveyand Bibliography on Attainmentof Laminar Reduction. Symposium held at VoughtAdvanced ~ ~". Flow Controlin Air UsingPressure Gradient and TechnologyCenter, Dallas, Texas, Nov. 7 and 8, Suction - Vol. I. NASA -1035, Sept.1979," 1979. AIAA TechnicalPapers, "Progress in 346 pp.,616 refs. Astronauticsand Aeronautics," Volume 72,1980, 481 pp. N79-33438# A8 1- 2650 1 This surveyand bibliography on attainmentof laminarflow in air throughthe use of favorable The symposium focused onlaminar boundary pressuregradient and suction consists of two layers,boundary layer stability analysis of a volumes. Volume I contains the survey, summaries natural laminar flaw glove on the F- 11 1 TACT air- of datafor both ground and flight experiments, craft, drag reductionof an oscillating flat plate and abstracts of referenced reports. Volume 11, withan interface film, electromagnetic pre- NASA 'IM-80108(X79- 10184#) comprises a bibliog- cipitation andducting of particles inturbulent raphyand abstracts of the restricted and classi- boundarylayers, large eddybreakup scheme for fiedlaminar flow control (LFC) literature. The turbulentviscous drag reduction, blowing and suc- firstauthor conducted the survey andcompiled tion, polymer additives, andcompliant surfaces. summariesof data, and the second author conducted Topics includedinfluence of environment in lami- theliterature search andcompiled the bibliog- narboundary layer control, generation rate of raphy. A thirdselected bibliography oflaminar turbulentpatches in the laminar boundary layer flowcontrol reports, available to NASA personnel of a submersible,drag reduction of small ampli- only,can be secured from the Scientific and tuderigid surface waves,and hydrodynamic drag TechnicalInformation Facility by askingfor NASA and surfacedeformations generated by liquidflows 'IM-80157 (X79-10185#). overflexible surfaces.

*NASA, Langley%search Center, Hampton, Va. 'Vought Advanced TechnologyCenter, Dallas, Texas **NASA, LangleyResearch Center, Hampton, Va. Supported by: U.S. Navy, U.S. Air Force, NSF, and (retired) NASA. (Note: Selected papers from this symposium follow. ) 142. Wigeland, R. A.; *Tan-Atichat, J.; and *Nagib, H. M. : Evaluation of a New Concept for Reducing EYee-Stream lbrbulencein Wind Tunnels. 144.*Leehey, P.: Influenceof Environment in NASA CR-3196, OCt. 1979, 49 pp. LaminarBoundary Layer Control. In: Viscous Flow Drag Reduction, Symposium, Dallas, Texas, Nov.7- N79-33440# 8, 1979. AIAA TechnicalPapers (A81-26501), 1980, Vola 72, pp. 4-16. The feasibility of using of a 45deg- honeycomb forimproving the flow quality in wind A81-26502# tunnels was investigated. The resultsof the experimentsindicate that the turbulence levels in TransitionReynolds number is not a unique a wind tunnelusing the 45 deg-honeycomb would be function of stream turbulencepercentage, but is comparable to thoseobtainable using a conven- influenced by thefrequency spectra, spatial tional honeycomb, i.e., a honeycomb which is scales, and otherphysical properties ofthe dis-

32 turbanceenvironment of the particular test providingan extremely high L/D = 240. This facility and by the physical characteristics of laminarairfoil design concept integrates passive the test plate. Hot-wiremeasurements ofbound- laminarflow stabilization, by pressuregradient arylayer disturbances shw that the response to shaping,with active diffusion control techniques streamturbulence, to downstream traveling acous- onthe airfoil trailing edge. A discussion of the tic waves,and to test plate vibration is primar- designconcept and the predicted performance is ilyin the Tollmien-Schlichting (FS) fundamental given. Full scale Reynolds number experiments eigenmode. Growth rates of T-S waves areini- defining maximum transition Reynolds number and tiallygreater under two-dimensional acoustic environmentinfluence on transition are presented. wave excitationthan under three-dimensional stream turbulenceexcitation in accordance with *VoughtAdvanced TechnologyCenter, Dallas, Tex. predictions from spatialstability theory. Con- Contracts N62269-77-C-0442 and N62269-79-C-0277 version of environmentaldisturbances to !l"S waves (Note:For this work inreport form, see #200 in is found to ocm primarily in the vicinity of 'the thisbibliography.) test plateleading edge. Analytical, numerical and experimentalresults suggest strongly that the efficiency of conversionincreases with increased 147.*Pfenninger, W.; **Reed, H. L.; and bluntness of theleading edge. ***Dagenhart, J. R.: DesignConsiderations of Advanced Supercritical Low DragSuction Airfoils. *Mass. Inst. ofTech., Cambridge, Mass. In:Viscous Flow DragReduction; Symposium at NSF-Navy-supported research. Dallas,Wxas, Nov. 7-8, 1979. AIAA Technical Papers (A81-265011, 1980,Vol. 72 of"Progress in Astronautics and Aeronautics," pp. 249-271. 145. *Famyan, L. J.; and**Steers, L. L.: BoundaryLayer StabilityAnalysis of a Natural A81-26514# Laminar Flow Glove on the F-111 TACT Airplane. In:Viscous Flow Drag Reduction, Symposium, Supercritical low dragsuction laminar flow Dallas,Texas, Nov. 7-8,1979, AIAA Technical airfoils were laidout for shockfree at design Papers(A81-26501), 1980, Vol. 72, pp. 17-32. freestream Mach = 0.76,design liftcoefficient = 0.58,and t/c = 0.13. The designgoals A81-26503# were theminimization of suctionlaminarization problemsand the assurance of shock-freeflow at A naturallaminar flow airfoil has been freestream Mach notgreater than design freestream developedas a part of the aircraft energy effi- Mach (fordesign lift coefficient) as well as ciencyprogram. A NASA flight programincorpora- atlift coefficient not greater than design lift ting this airfoil into partial winggloves on the coefficient(for design freestream Mach); this F- 111 TACT airplane was scheduled to start in involvedlimiting the height-to-length ratio of May, 1980. Insupport of thisresearch effort, an thesupersonic zone at design to 0.35.High extensiveboundary layer stability analysis of the designfreestream Mach numbers resultwith exten- partialglove has beenconducted. The results sivesupersonic flow (over 80% ofthe chord) on of thatanalysis show theexpected effects of wing theupper surface, with a steepStratford-type leading-edge sweep angle,Reynolds number, and rearpressure rise withsuction, as well as by compressibility on boundary layer stability and carryinglift essentially in front- andrear- transition. These resultsindicate that it should loadedregions of the airfoil with high static be possible to attain on theorder of 60% laminar pressures on thecarved out front and rear lower flow on theupper surface and 50% laminarflow on surf ace. thelower surface for sweep angles of at least 20 deg,chord Reynolds numbersof 25 x lo6 and *GeorgeWashington Univ., Wash., D. C. Mach numbersfrom 0.81 to 0.85. **VirginiaPolytechnic Institute, Blacksburg, Va. ***NASA, LangleyResearch Center, Hampton, Va. *BoeingCommercial Airplane Co., Seattle, Wash. **NASA, Dryden FlightResearch Center, Edwards, Calif. 148. *Poll, D. I. A.: Transitionin the Infi- nite Swept AttachmentLine Boundary Layer. The AeronauticalQuarterly, vol. 30, Nov. 1979, 146. *Mask, R. L.: JAW Drag Airfoil Design Uti- pp. 607-629. lizing Passive Laminar Flow Controland Coupled DiffusionControl. In: "Viscous Flow Drag Reduc- A80- 13573 tion" Symposium at Dallas,Texas, Nov. 7-8. 1979. AIAA TechnicalPapers (A81-265011, 1980,Vol. 72 The transitionbehavior of the boundary layer of "Progressin Astronautics and Aeronautics ," which is formedalong an infinite swept attachment pp. 212-232. linehas been studiedexperimentally. Circular trip wires and turbulent flat plate boundary A81-26512# layershave been used as sources of disturbance andthe range of parameters coveredhas been such A two-dimensionalhigh-chord Reynolds number thatthe results are directly applicable to full passivelaminar airfoil was designedfor lift scale flightconditions. Simple criteria have coefficient = 0.73 at freestream M = 0.6 and beendeduced which allow the state of theboundary Re = 4 x lo7 (evaluated.for chord length) layer to be determinedfor given geometric and

33 F

free stream properties. Sample calculations for *A081255 N80-23602# typical swept wingconfigurations suggest that the majority of civil aircraft will haveturbulent Goertler instabilityfor boundary-layer flows attachmentlines in the cruise and that subsequent overgenerally curved walls is considered. The relaminarization in regionsof favorable pressure fulllinearized disturbance equations are obtained gradient is unlikely. inan orthogonal curvilinear coordinate system. A perturbationprocedure to account forsecond-order *Collegeof Aeronautics, Cranfield Institute of effects is used to determine the effects of the Technology,Beds., England displacementthickness and the variation of the Researchsupported by the Ministryof Defence. streamlinecurvature on theneutral stability of theBlasius flow. The pressuregradient in mean flow is accountedfor by solving the non-similar 149. *Pugh, P. G.; **Grauer-Carstensen, H.; and boundary-layerequations. Growth rates are ***Quemard, C.: An Investigation of themality obtained for the actual mean flowand compared ofthe Flow Generated by Three Typesof Wind withthose for the Blasius flow and the Falkner- Tunnels.In: AGARD "Towards New Transonic Wind- Skanflows. The resultsdemonstrate the strong Tunnels"(N80-19137), Nov. 1979,23 pp. influence of the pressuregradient and the nonsimilarityof the basic flow on the stability N80-19138# characteristics.

Flow quality in three wind tunnelswith dif- *VirginiaPolytechnic Institute and State Univ., fering drive systems is examined. The investi- Blacksburg, Va. gationincluded measurements of ( 1)fluctuating Contract N00014-75-C-0381. static pressure on thesidewall of the test section;(2) turbulence immediately upstream of the contraction and inthe test section;(3) fluctua- 152. Winoto, S. H.; *Durao, D. F. G.; and*Crane, tionsof flow angle (both pitch and yaw) inthe R. I.: MeasurementsWithin Grtler Vortices. test section; and (4)fluctuations of both pitot Journalof Fluids hgineering, Lkc. 1979, and static pressuresin the test sectionflow. VO~. 101, pp. 517-520. Factorsimportant to thedescription ofwind tunnelflow quality are also discussed. It is A80-20750# shown thatthe use of fluctuating static pressure as anindex of flow quality is invalid when com- Local measurementsof streamwise velocity paring wind tunnelshaving different formsof componenthave been made inthe laminar boundary drivesystem or, possibly,even widely different layer on theconcave surface of a water channel, types of test section.Fluctuations in flow angle supported by flowvisualization. Details ofthe are of much more directconsequence to thegather- naturally-occurring GGrtler vortex pattern are ingof the usual types of data andcan be measured presented. usingeither appropriately designed yawmeters or with hot-film probes. *Dept.of Mechanical Engineering, Imperial College ofScience and Technology, London, England *Royal AircraftEstablishment, Bedford, England Researchsupported by ScienceResearch Council. **DFVLRI Goettingen, West Germany ***CERT, Tbulouse,France

153. 'Bozatli. A. N.: Effectsof Wall~ Waviness andNonlinear Wave Interactions on the Stability 150. *Koegler,John A., Jr.: A Parametric Wing of Boundary-LayerFlows. Ph.D. Thesis,Virginia DesignStudy for a Modern Laminar FlowWing. PolytechnicInstitute and StateUniversity, 1979, ~~ - NASA-1M-80154, Dec. 1979, 44 pp. 186 pp. (Availablefrom University Microfilms, Order no.7924092.) N80- 15050# N80- 12992 The resultsof a parametricwing design study using a modern laminarflow airfoil designed to The effectsof wall undulations on the sta- exhibitdesirable stall characteristicswhile bility of andnonlinear mode-mode interactions of maintaininghigh cruise performance are presented. disturbance waves in boundarylayer flows are It was found that little is sacrificedin cruise investigated by using a combinationof perturba- performance when satisfying the stall margin tion andnumerical methods. Nonparallel flow requirements if a taper ratio of 0.65 or greater effects are retained in most of the cases treated. is used. The waviness on a plate whichcan stabilize or destabilizethe flow, depending on theflow and *NASA, LangleyResearch Center, Hampton, Va. waviness parameters is discussed.Stabilizing the flow by transferring energy from the unstable Tollmien-Schlichting mode to a higher stable mode 151. *-gab, S. A.; and*Nayfeh, A. H. : through a resonant wave coupling mechanism is Goertler Instability. VPI-E-79-41,Dec. 1979, 81PP-

34 examined. Firstorder linear secondary instabil- ference scheme is developedfor solving the lower ities associatedwith a time dependentflow con- deckequations. The theory is appliedto super- L,! I sisting of thesuperposition of a basicflow and a sonicflows past compression ramps andincompres- finiteamplitude fundamental wave are analyzed. sibleflows over small humps with small bubble separation. Also a numerical method forintegrat- DissertationAbstracts. ingthe interacting boundary layer equations for incompressibleflows is developed.For incompres- *VirginiaPolytechnic Institute and State Univer- sibleflows over small humps the first order sity,Blacksburg, Va. theory is in good agreementwith the interacting boundary layer. By includingthe second order termsin the triple deck theory, better agreement 154. *Aircraft Ehergy Efficiency Program: laminar is obtained. For supersonicflows past corners, Flow ControlTechnology. NASA-7"-82352, the agreementbetween the triple deck theory and NF-86/8-79, 1979, 8 pp. solutions of thefull Navier-Stokes equations is improvedonly inthe free interaction region for N81-24389# anadiabatic wall. The secondorder theory breaks down forcold walls. Laminarflow control system design is ana- lyzedwith emphasis on surface and structural con- *VirginiaPolytechnic Institute and State Univ., cepts, wing structures,leading edge contamination Blacksburg, Va. andsuction unit configurations.

(This type of publication is known as a "NASA 157. *Dougherty, N. S., Jr. ; and**Fisher, D. F. : FACT. " ) Boundary-Layer Transition ona IO-Deg. Cone-Wind *NASA, wash., D.C. Tunnel/FlightCorrelation. AIAA 18thAerospace ScienceMeeting, Pasadena, Calif ., Jan.14-16, 1980, 17 pp. 155. *Nayfeh, A. H.; and*El-Hady, N. M.: Nan- parallel Stability ofTwo-Dimensional Nonuniformly AIAA-80-0154 A80-22737X HeatedBoundary-Layer Flows. NASA CR-162309, VPI-E-79-1; 1979, 37 pp.Also, Physics of Fluids, Boundary-layer transitionlocation measure- vol. 23, 1980,pp. 10-18. mentswere madeon a 10-deg sharpcone in 23 wind tunnels of the U.S. andEurope and inflight. The N79-32499X data were acquiredat subsonic, transonic, and supersonic Mach numbersover a rangeof unit An analysis is presentedfor the linear sta- Reynoldsnumbers toobtain animproved understand- bility of waterboundary-layer flows over nonuni- ing of wind tunnelflaw quality influence. Cone formlyheated flatplates. Included in the surface microphonemeasurements showed Tollmien- analysis are disturbances due tovelocity, pres- Schlichting waves present.Transition location sure,temperature, density, and transport defined by pitotprobe measurements showed transi- propertiesas well asvariations of theliquid tion Reynolds number to be correlatableto cone propertieswith temperature. The method of surfacedisturbance amplitude within + or - 20 multiplescales is usedto account for the nonpar- percentfor the majority of tunneland flight allelism of the mean flow. In contrastwith data. previousanalyses, the nonsimilarity of the mean flow is takeninto account. No analysisagrees, *ARO, Inc.,Arnold Air Force Station, Tenn. evenqualitatively, with the experimental data *NASA, Dryden FlightResearch Center, Edwards, when similarprofiles are used. However, boththe Calif. parallel and nonparallelresults qualitatively agreewith the experimental results of Strazisar andReshotko when nonsimilarprofiles are used. 158.*Mercer, J. E. ; *Geller, E. W. ; *Johnson, M. L.; and**Jameson, A.: A Computer Code to *VirginiaPolytechnic Institute and State Univ., Model Swept Wings in anAdaptive Wall Transonic Blacksburg, Va. Wind Tunnel. Flow Research&pt. no. 164, May 1980. Presented at the AIAA 18thAerospace SciencesMeeting, Pasadena, Calif., Jan. 14-16, 156.*-gab, S. A.: InteractingInviscid and 1980, 7 pp. LaminarViscous Flow, and Some Aspects of the Stability. VPI and SU Ph.D. Thesis,1979, A80- 207pp. AIAA-80-0156 19287# (Availablefrom University Microfilm, Order no. 8020226.) A computerprogram has been developed to cal- culateinviscid transonic flow over a sweptwing N80-30679 in a wind tunnelwith specified normal flow at the walls. An approximatelyorthogonal computa- The method of matchedasymptotic expansions tional grid whichconforms to the wingand the is used to obtain a secondorder triple decksolu- tunnelwalls was developedfor application of the tionfor the case of constantwall temperature. Jameson-Caughey finite volume algorithm. The code It includesthe problem of an adiabaticwall as a solvesthe full potential equations in fully con- special case. A secondorder accurate finite dif- servative formusing line relaxation. This pro-

35 gram is to be used in place of the wind tunnel for cesses involved are the same. A spectral and preliminarystudies of theadaptive wall concept finitedifference numerical algorithm is employed for threedimensional configurations. It canalso in the simulation. be used to assess the magnitudeof wall interference in a conventionaltunnel. *NASA, Ames ResearchCenter, Moffett Field, Calif. **ICASE, NASA, LangleyResearch Center, Hampton, *Flow Research Co., Kent, Wash. Va . **New York Univ., New York, N. Y. Contract No. F40600-79-C-001. 161. fwilcox, D. C.: Developmentof an Alternative to the e9 Procedurefor Predicting 159. *El-Hady, N. M.; and 'Nayfeh, A. H.: Nonpar- Boundary ldyerTransition. Presented at the AIAA allel Stability of Compressible -Boundary-Layer 18thAerospace Sciences Meeting, Pasadena, Calif., Flows. Presented at the AIAA 18thAerospace Jan. 14-16, 1980, 14 pp. SciencesMeeting, Pasadena, Calif., Jan. 14- 16, 1980. AIAA-80-0278 A80- 18289#

AIAA-80-0277 A method hasbeen devised which can be used inconjunction with linear-stability theory for The effect of compressibility on thestabil- predictingboundary-layer transition. As withthe itycharacteristics of boundary-layerflows is classical lle911 procedure,for a givenfrequency investigatedwithin the framework of a complete the growth of a disturbance is computeddownstream nonparallel,linear, spatial stability theory. ofthe initial point of instabilityusing the The methodof multiplescales is used toaccount linearizedequations ofmotion. In contrastto forthe nonparallelism of the mean flowand an the e9 procedurein which thelinearized equations equation is derivedfor the modulation of the wave areused all the way to the inferred transition amplitudewith position. Stability characteris- point, an approximate set oflong-time averaged tics are examined for boundary-layerflows over an equations whichaccount for nonlinearity is used adiabaticflat plate. A nearlyconstant increment to describethe ultimate nonlinear growth of the in the growth rate due tononparallel effects is disturbance.Because the new method accountsfor found forsubsonic flows. For supersonicflows, nonlinearprocesses it holdspromise as amore thiseffect is a function of wave angle.Oblique physically soundprocedure than the e9 method for first-mode waves are more unstablethan two- determiningthe point at which a boundarylayer dimensional waves according to both parallel and undergoestransition to turbulence. nonparalleltheories. For the second-mode the mostunstable frequency predicted by the nonpar- *DCW Industries,Inc., Studio City, Calif. allel theoryfor a givenReynolds number is higher Contracts NOR N00014-77-C-0259 and thanthat predicted by theparallel theory, in NOOO14-78-C-0799. contrastwith the first-mode results where they are equal. The nonparallelresults are in better agreementwith the experimental results of Laufer 162. Cotta, R.: IncreasingAircraft Efficiency andVrebalovitch and Kendall than the parallel ThroughLaminar Flow Control.Aviation resultsfor M < 2.2. Engineeringand Maintenance, vol. 4, Jan. 1980, pp. 12-15. *VirginiaPolytechnic Institute and State Univ., Blacksburg, Va. A80- 24899

The articlediscusses recent work in improv- 160. Wray,Alan; and **Hussaini, M. Y.: Numeri- inglaminar flow in order to reduce drag and calExperiments in Boundary-Layer Stability. AIAA therebyoverall fuel consumption. Attention is 18thAerospace Sciences Meeting, Pasadena, Calif., givento NASA's laminarflow control project Jan. 14-16, 1980, 9 pp. (LFC) , the object ofwhich is todemonstrate that thetechnology required to incorporate LFC into AIAA-80-0275 A80-23957# long-rangecommerical jettransports of the1990's is available.Discussion covers LFC aircraft Numerical solutionof the three-dimensional configurationsproposed by Boeing,Lockheed, and incompressibleNavier-Stokes equations is usedto Douglas.Also covered are computer aided design, studythe instability of a flat-plate boundary possiblematerials, and compromises for mainte- layer in a manneranalogous to the vibrating- nanceaccess. Finally, attention is givento ribbonexperiments. Flowfield structures are losses in aerodynamicefficiency which stem from observedwhich are very similar to those found in insectaccumulation on wingleading edges, dents, thevibrating-ribbon experiment to whichcomputa- mismatched surfacepanels, and leaking pressuriza- ational initial conditions havebeen matched. tion ofaerodynamic seals. Streamwiseperiodicity is assumed inthe simulation so thatthe evolution occurs in time, but theevents which constitutethe instability are 163. 'Mabey, Dennis G.: ResonanceFrequencies of so similarto the spatially occurring ones of the Ventilated Wind Tunnels. AIAA Journal,vol. 18, laboratorythat it seems clearthe physical pro- no. 1, Jan. 1980, pp. 7-8 (Synoptic).

36 N79-30245 (full paper) 166. *Klopfer, G. H.; and **Hussaini, M. Y.: -A Study .of Formation of Intense Shear Layers in Experiments suggest that the theory widely ..Transitional Boundary Layers. ICASE Rept. used to predict the transverse resonance frequen- No. 80-5, NASA CR-165,909, Jan. 31, 1980, 31 pp. cies in slotted tunnels is in error in the 0-0.05 Mach number range. One reason for the error is The present study is an analytical investiga- that the theory is based on an unrepresentative tion of the initial stages to turbulence in an wall boundary condition. Moreover, the theory incompressible boundary layer on a flat plate. An implies that the plenum chamber depth is generally attempt is made to obtain a conceptual picture of less than twice the tunnelheight. An improved the development of laminar instability with par- theory is developed which shows that the resonance ticular reference to three-dimensional nonlinear frequencies of ventilated tunnels are influenced phenomena. The analytical study is based on cer- by the depth of the plenum chamber for Mach nun+ tain physical assumptions, and some comparisons bers up to about M = 0.6. Although the theory is with experiments are carried out to test these approximate, it agrees well with experiments for assumptions. The agreement between the two estab- slotted and perforated walls (with both normal and lishes confidence in the final results. 60 deg inclined holes) in a small pilot wind tunnel (100 x 100 m). The earlier theory was only It is shown that the development of a two- valid for slotted working sections. The results dimensional disturbance into a three-dimensional are consistent with other experiments, which show configuration associated with streamwise vortices that plenum chamber design can influence the flow is a nonlinear phenomenon, at least in the cases unsteadiness within the working section of a investigated. Its subsequent evolution to intense ventilated tunnel. shear layers is essentially an inviscid linear phenomenon, though nonlinear effects modify the *Royal Aircraft Establishment, Bedford, England magnitude of the relevant characteristic properties. The influence of various initial perturbation profiles on the development of high shear 164. *Lekoudis, S. G.: Resonant Wave Interac- layers is brought out. tions on a Swept Wing. AIAA Journal, vol. 18, Jan. 1980, pp. 122-124. 'Nielsen Engineering and Research, Inc., Mountain View, Calif. A80- 17006# **Institute for Computer Applications in Science and Engineering (ICASE) NASA, Langley Research !rhe nonlinear stability of a three- Center, Hampton, Va. dimensional boundary layer flow on a swept wing Contracts NASI-14101 and NAS1-14472. with laminar flow control is considered in terms of resonant wave interactions. For a locally parallel, three dimensional boundary layer flow 167. *-glia, G. L.; and *Wilkinson, S. P.: consisting of a steady mean part and an unsteady Experimental Study of Flow Due to an Isolated Suction Hole and a Partially Plugged Suction disturbance part consisting of wave triads, it is -~~~ found that the disturbance is governed by the -Slot. Final Report, Feb. 1, 1978 - Jan. 31, Orr-Somerfeld problem for the case of a three- 1980. NASA CR-162808, Feb. 1980, 36 pp. dimensional boundary layer. A set of quasi- linear, first-order, partial differential equa- N80- 18340# tions for the slowly varying disturbance amplitudes is then derived from the resonance condi- Details for construction of a model of a tions. It is shown that the necessary conditions partially plugged, laminar flow control, suction for resonant interaction exist for crossflow slot and an isolated hole are presented. The instability waves on a typical laminar flow con- experimental wind tunnel facility and instrumenta- trol wing, and implications for the prediction of tion is described. Preliminary boundary layer transitions on swept wings are discussed. velocity profiles (without suction model) are presented and shown to be in good agreement with the *Lockheed-Georgia Co., Marietta, Ga. Blasius laminar profile. Recommendations for the completion of the study are made. An experimental program for study of transition on a rotating disk 165. *Orszag, S. A.: Advanced Stability Theory is described along with preliminary disturbance Analyses for Laminar Flow Control. Final Report. amplification rate data. NASA CR-3233, Feb. 1980, 50 pp. *Old Dominion Univ., Norfolk, Va. N80- 17396# Grant NSG- 1491

Recent developments of the SALLY computer code for stability analysis of laminar flow con- 168. *El-Hady, Nabil M.: Nonparallel Stability trol wings are summarized. Extensions of SALLY to of Three-Dimensional Compressible Boundary study three dimensional compressible flows, non- Layers. Part I - Stability Analysis. Final parallel and nonlinear effects are discussed. Rept. NASA CR-3245, Feb. 1980, 38 pp.

*Cambridge Hydrodynamics, Inc., Cambridge, Mass. N80- 16296# Contract NAS1- 15372

37 A compressiblelinear stability theory is trol wings are summarized.Extensions of SALLY to presentedfor nonparallel three-dimensional studythree dimensional compressible flows, non- boundary-layerflows, taking into account the parallel andnonlinear effects are discussed. normal velocity component as well as the streamwise andspanwise variations of the basic flow. *CambridgeHydrodynamics, Inc., Cambridge, Mass. The method ofmultiple scales is used to account Contract NAS1-15372 forthe nonparallelism of the basic flow,and equations are derivedfor the spatial evolutionof the disturbanceamplitude and wavenumber. The 172. *Batill, S. M.; andWueller, T. J.: Visual- numericalprocedure for obtaining the solution of izationof the Laminar-Turbulent Transition in the the nonparallel problem is outlined. Flow over anAirfoil Using the Smoke-Wire Tech- nique. AIAA 11thAerodynamic Testing Conference, *Old Dominion Univ.,Norfolk, Va. ColoradoSprings, Cnlo., March 18-20,1980. In Grant NSG- 1645 TechnicalPapers (A80-269291, 1980,pp. 45-53.

1 A80-26935#AIAA-80- 042 1 169. *Schairer, Edward T.: TurbulenceMeasure- ments in the BoundaryLayer of a Low-SpeedWind A flowvisualization technique, referred to TunnelUsing Laser Velocimetry. NASA TM-81165, as the smoke-wire, was usedfor visualization of Feb. 1980, 25 pp. thetransition of the free shear layer associatedwith the laminar separation bubble of a N8O- 16300# NACA 663-018 airfoil section at low Reynolds number (50,000-130,000). The smoke-wire technique Laservelocimeter measurements in an incom- allowsthe introduction of fine smoke streaklines pressible,turbulent boundary layer along the wall intothe flow field through the electrical resis- of a low-speed wind tunnel are presented. The tive heatingof a very fine wire whichhas been laser data are compared withexisting hot-wire coatedwith oil andwhich is locatedupstream from anemometermeasurements of a flat plate, incom- theleading edge of the airfoil section.Streak- pressible,turbulent, boundary layer with zero line data were collectedusing both high speed pressuregradient. An argument is presented to still andmotion picturephotography. explain why previous laser velocimetermeasure- ments inzero pressure gradient, turbulent bound- *Notre Dame Univ., Notre Dame, Ind. arylayers have shown anunexpected decrease in Grant NSG 1419 turbulentshear stresses nearthe wall.

*NASA, Ames ResearchCenter, Moffett Field, Calif. 173.*Pate, S. R.: Effectsof Wind TunnelDistur- bance on Boundary-Layer Transitionwith ~Ehphasis onRadiated Noise: A Review. (Invitedpaper), 170. *Nayfeh, A. H.; and*Padhye, A.: Neutral AIAA 11th Aerodynamic TestingConference, Colorado StabilityCalculations for Boundary-LayerFlows. Springs, Colo., March 18-20, 1980, 22 pages + Physicsof Fluids, vol. 23,Feb. 1980, 80 figures. pp. 24 1- 245. AIAA-80-0431 A80-25852 Effects ofwind tunnelfree-stream distur- An analysis is presentedof the parallel banceson boundary-layer transition are reviewed. neutralstability of three-dimensional incompress- Experimentalresults show that free-stream dis- ible,isothermal boundary-layer flows. A Taylor- turbancesdominate the transition process as series expansionof the dispersion relation determined by theexperimentally measured transi- is used to derivethe general eigenvalues. These tion Reynolds numbers on simple geometries(flat equations are functionsof the complexgroup platesand sharp cones). Principal modes of dis- velocity. These relations are verified by numer- turbance are turbulence (;/Urn) and acousticsound ical resultsobtained for two- andthree- (p/q,) at subsonicspeeds; hole/slot acoustic dimensionaldisturbances in twc- andthree- resonance at transonicspeeds (p/q,); and tunnel dimensionalflows. wall turbulent-boundary-layerradiated - noise at supersonic-hypersonicspeeds (p/q,). Data corre- *VirginiaPolytechnic Institute and State Univ., lationsand resulting empirical equations that Blacksburg, Va. show thedirect relationship between transition Grant NSG 1255 Reynoldsnumbers and free-stream disturbance levels are presentedand discussed.

171.*Orszag, Steven A.: Advanced Stability *ARO, Inc., AEDC Division,Arnold Air Force Sta- TheoryAnalyses for Laminar Flow Control. NASA tion, Tenn. CR-3233, February1980, 48 pp.

N80-17396# 174. Wigeland, R. A. ; *Tan-Atichat, J. ; and *Nagib, H. M.: Evaluationof a New Conceptfor Recentdevelopments of the SALLY computer ReducingFree-Stream Turbulence in Wind Tunnels. codefor stability analysis oflaminar flow con- AIAA 11th Aerodynamic TestingConference,

38 ColoradoSprings, Colo., March 18-20, 1980- In Additional tests were conducted to further TechnicalPapers (A80-269291, AIAA, Inc.,1980, definethe disturbance characteristics of the pp. 117-128. Also, Journalof Aircraft, vol. 18, Langley*Foot Transonic Pressure Tunnel. July 1981, Pp. 528-536. Measurements were made in the settling chamber withhot wire probesand in the test sectionwith AIAA-80-0432 pressuretransducers A80-26942# when various methods were used to choke theflow. In addition to present- A 45deg-honeycomb flowmanipulator, mounted ing rms valuesmeasured at variouslocations and parallel to thecorner turning vanes, was inves- tunnelcondition, autocorrelations and cross cor- tigatedfor improving the flow quality in wind relation data are also presented. tunnelswith little or no settling chamber length. Thismanipulator permits increasedturbulence *NASA, LangleyResearch Center, Hampton, Va. decaydistance in comparison to a conventional honeycomb arrangement. The resultingturbulence levels in a wind tunnel using the 45 deg-honeycomb 177. 'Nayfeh, A. H.; *Bozatli, A. N.: Nonlinear are comparable to those obtained using a conven- Interaction of 'Ruo Waves in Boundary-Layer tional honeycomb, butonly when a 45 deg-screen Flows.Physics of Fluids, vol. 23, March 1980, is mounted immediatelydownstream of the honeycomb pp. 448-458. and when some separationdistance between the turningvanes and the 45deg-honeycomb is provided A80-30535 foradequate decay of the turningvane wakes (at least twice thespacing between the turning First-ordernonlinear interactions of vanes) . Tollmien-Schlichting waves of differentfrequen- cies and initialamplitudes in boundary-layer *IllinoisInstitute of Technology, Chicago, Ill. flows are analyzedusing the methodof multiple Grant NsG- 1451. scales. Numerical resultsfor flow past a flat plate show that thespatial detuning wipes out resonantinteractions unless the initial ampli- 175.*Scheiman, James; and*Brooks, J. D.: -A tudes are verylarge. Thus, a wave having a Comparisonof Experimental and Theoretical moderateamplitude has little influence on its TurbulenceReduction from Screens, Honeycomb and subharmonicalthough it has a stronginfluence on Honeycomb-Screen Combinations. AIAA 11th its secondharmonic. Moreover, two waves having Aerodynamic TestingConference, Colorado Springs, moderateamplitudes have a stronginfluence on Colo., March 18-20, 1980, TechnicalPapers, 1980, theirdifference frequency. The results show that pp. 129-137. thedifference frequency can be veryunstable when generated by thenonlinear interaction, even AIAA-80-0433-CP AEO- 26943# though it my be stable when introduced by itself inthe boundary layer. A 1/2-scalemodel of a portionof the NASA Langley8-Foot Transonic Pressure Tunnel was used *VirginiaPolytechnic Institute and State Univ., to conduct some turbulencereduction research. Blacksburg, Va. The experimentalresults are correlatedwith Contract N00014-75-C-0381. varioustheories. Screens alone reduce axial Grant NSG- 1255. turbulence more thanthe lateral turbulence; whereas, honeycomb alonereduces lateral turbulence mre thanaxial turbulence. Because of this 178. *Quast, Armin: Laminar Airfoilsfor difference,the physical mechanism fordecreasing TransportAircraft. "Laminarprofile fuer turbulencefor screens and honeycomb mst be corn verkehrsflugzeuge"Fept. DFVLR-Mitt-80-07, pletelydifferent. Honeycomb with a downstream March 1980, 34 pp. Translationinto English screen is anexcellent combination for reducing ESA-TT-680 by European Space Agency. Paris, turbulence. France, Oct. 1981,33 pp.

*NASA, Langley Research Center, Hampton, Va. N81-13952# (In German) (Note: A revisedversion of this paper was pub- N82-18190# (InEnglish) lishedin the Aug. 1981 issueof the Journal of Aircraft, pp. 638-643,#241 inthis bibliography.) Thedevelopment of laminar airfoils in order to save fuel by reducingdrag is discussed. Laminarizationthrough shaping is considered. 176.*Brooks, J. D.; *Stainback, P. C.; and Laminarand turbulent boundary layer theory and *Brooks, C. W., Jr. : Additional Flow Quality subjectiveassessment indicate that laminar air- Measurements inthe Langley Research Center 8-Foot foilsfor high Reynolds numbers are feasible,with TransonicPressure Tunnel. Presented at the AIAA a 22% fuelsaving. The reducedcruising speeds, 11thAerodynamic Testing Conference, Colorado required,however, decrease passenger comfort, Springs, Colo., March 18-20, 1980. Technical making them more suitablefor freight carrying. Papers, 1980, pp. 138-145. *DeutscheForschungs- und Versuchsanstalt fuer AIA A -80-0434 -CP A80-26944# AIAA-80-0434-CP Luft-und Faumfahrt, Brunswick (West Germany)

39 179.fDougherty, N. S., Jr.: Influence of Wind 182. *Cebeci, Tuncer;and **Stewartson. Keith: Tunnel Noise on theLocation of BoundaryLayer On Stabilityand Transition in Three-Dimensional ~~ ~ Transition on a Slender Cone at Mach Numbers from Flows.Presented as AIAA-79-0263 at the17th 0.2 to 5.5, Vol. 11: Tabulatedand Plotted Data. AerospaceSciences Meeting, New OTleans, La., AEDC-TR-78-44, vol. 2. Final Rept., Jan.26, Jan. 15-16, 1979. AIAA Journal, vol. 18, no. 4, 1970 - Apr. 28,1977. March 1980, 246 pp. April 1980, pp. 398-405.

-A083166 AIAA-74-0263RN80-26280#

A study was conducted to investigate the (For abstract see citation#lo5 in this effectsof wind tunnel test sectionnoise on the bibliography. ) locationof boundary-layer transition. The study was carriedout by conductingexperiments on a *California State Univ., Long Beach, Calif. slender,highly polished cone with an included **UniversityCollege, London, England angleof 10 deg. Wind tunnel test sectionnoise was measured by microphonesflush-mounted on the conesurface. In most ofthe experiments, 183. 'Hefner, J. N.; and*Bushnell, D. M.: Status boundary-layertransition was measuredwith a ofLinear Boundary-Layer Stability and the e" surface-mounted,traversing pitot pressure Method, withEmphasis on Swept-Wing Applications. probe. The experiments were conducted in 23 dif- NASA TF1645,April 1980, 50 pp. ferentsubsonic, transonic, andsupersonic wind tunnels over a Mach number rangefrom 0.2 to 5.5 N80-22633# and a unitReynolds number rangefrom 1.0 X IO6 to 7.0 x lo6per foot, the bulk of thedata being The state-of-the-art for theapplication of obtainedbetween 2.0 x lo6and 4.0 X lo6 per foot. linear stability theory and the en method for The results show an influenceof wind tunnelnoise transitionprediction and laminar flow control on boundary-layertransition for most of the wind design are summarized,with analyses of previously tunnels. published low disturbance, swept wing data presented.For any set oftransition data with *ARO Inc., a SverdrupCorp., Co., Arnold Air Force similar stream disturbancelevels and spectra,the Station, Tenn. en method forestimating the beginning of transition works reasonably well; however, thevalue of ncan vary significantly, depending upon varia- 180.Zhigulev, V. N.; Kirkinskiy, A. T.; tionsin disturbance field or receptivity. Where Sidorenko, N. V.; and Tumin, A. M.: The Mechanism disturbance levelsare high, the valuesof n are ofSecondary Instability and Its RDle in the appreciably below theusual average valueof 9 to Generationof Turbulence. Fluid Mechanics - 10 obtainedfor relatively low disturbancelevels. SovietResearch, vol. 9, no. 2, Mar./Apr. 1980, It is recommended thatthe design oflaminar flow pp. 96- 114. controlsystems be based on conservative estimates of n and that,in considering the values of n The developmentof disturbances in the bound- obtainedfrom different analytical approaches or arylayer after loss of stability is analyzed, investigations,the designer explore thevarious concentrating on thethree-dimensional nonlinear assumptionswhich entered into the analyses. perturbing wave. A mechanism ofsecondary instability of theperturbing wave in the boundary *NASA, LangleyResearch Center, Hampton, Va. layer is suggestedand the role of this mechanism ingeneration of turbulence is examined. The calculations made are comparedwith experimental 184.*Orszag, Steven A.: StabilityAnalysis for data and a statistical approach to theproblem of Laminar Flow Control - Part 11, Final Report. hydrodynamic instability to reveal the role of NASA CR-3249, April 1980, ~20~pp. secondaryinstability in the development offlow turbulence. N80-21703#

Topics coveredinclude: (1) optimization of 181.'Nayfeh, Ali H.: Stability of Three- the numerics of the SALLY stabilityanalysis code; DimensionalBoundary Layers. Presented as (2)relation betweentemporal and spatial stabil- AIAA-79-0262 at the17th Aerospace Sciences Meet- ity theory; ( 3) compressibleflow stability cal- ing, New Orleans, La., Jan. 15-16, 1979. AIAA culations;(4) spectral methods forthe boundary Journal, vol. 18, no. 4, April 1980,pp. 406-416. layerequations; and (5) numerical study of nonlinear,nonparallel stability of incompressible AIAA-79-0262R flows.

(Forabstract see citation#lo4 in this *CambridgeHydrodynamics, Inc., Cambridge, Mass. bibliography. ) Contract NAS1-14907 (Note:For Part I, see citation #58 inthis 'VirginiaPolytechnic Institute and State Univ., bibliography. ) Blacksburg, Va. Grant NSG 1255

40 &)&< 185. *Beall, R. T.: Fabrication of a Graphite/ 180-26293C Epoxy CompositeLeading Edge for Laminar Flow 4"4 Control.In the Society for the Advancementof Alternateconcepts and design approaches were Material andProcess Engineering (SAMPE) Proceed- developedfor suction panels, and techniques were ings of the25th National Symposium andExhibi- definedfor integrating these panel designs into a tion, San Diego, Calif., May 6-8, 1980, complete LFC200R wing. The designconcepts and (A81-22636), pp.243-250. approaches were analyzedto assure that they would meet thestrength, stability, and internal volume A81-22652 requirements.Cost and weight comparisons of the concepts were also made. Problems of integrating Lockheed hasrecently completed the first theconcepts into a completeaircraft system were phaseof a program to evaluatelaminar flow con- addressed.Methods for making splices both chord- trolconcepts for transport aircraft. Achievement wise andspanwise, fuel light joints, and internal oflaminar flow over a wing surfacerequires a ductinstallations weredeveloped. Manufacturing systemof slots, meteringholes, ducts and pumps problemssuch as slotalignment, tapered slot to be used to remove the turbulent air adjacent spacing,production methods, and repair techniques to thesurface. This requirement poses severe were addressed. An assessment of theprogram was restrictions on conventional metallic structure. used to developrecommendations for additional Graphite/expoxycomposite with its uniqueproper- researchin the development of SPF/DB for LFC ties appears to be the material that mightsolve structure. the verycomplex structural problemsassociated with a laminarflow control aircraft. A six-foot *Rockwell International Corp., Aircraft Div., Ins spangraphite/epoxy test articleincorporating Angeles,Calif. provisionsfor leading edge cleaning, deicing and Contract NAS1- 15488 laminarflow control was designed,fabricated and tested. 188.*Tan-Atichat, Jimmy: Effects of Axisymmetric *Lockheed-Georgia Co., Marietta, Ga. Contractions on Turbulenceof Various Scales. NASA-supported research. IllinoisInst. ofTech., Chicaso, -.Ph.D. Thesis, 1980, 393pp. (Order No. 8026159from University Microfilms.) 186.*Chan, Y. Y.: BoundaryLayer Controls on the Sidewalls of Wind Tunnels for Two-Dimensional N81- 13055 Tests. Journal of Aircraft,vol. 17. May 1980, pp.380-382. The presentstudy examines digitally acquired andprocessed results from an experimentalinves- A80-33281# tigation of grid-generatedturbulence of various scalesthrough and downstreamof ninematched The sidewall boundary layer in a transonic cubicaxisymmetric contractions ranging in area wind tunnel test sectionfor a two-dimensional ratio from 2 to 36, and in length-to-inlet diam- airfoil is turbulent andcompressible in general. eter ratio from 0.25 to 1.50.In addition,a The presentnote provides some results of the fifthorder contraction was utilizedfor studying sidewall boundary layer developments correspond- thecontour shape effect. Key features of this ing to two specified boundarylayer growth con- experimentincluded powering the wind tunnelwith trol methods. A detailedexamination gives a compressed air to eliminate minuteextraneous betterunderstanding of the phenomena with which velocityfluctuations caused by theblower fan themerits or inadequacyof the control methods blades which amplifyand affect the components of can be assessed. In summary, by applyingsuction turbulentkinetic energy unequally in a contract- at an area of theside wall around the model,one ingstream, and the concurrent utilization ofboth canactively control the boundary layer growth, digital andanalog instrumentation to achieve a andconsequently the inviscid flow outside the higherquality of therecorded data. Results boundarylayer can be made practically parallel to indicate that the extent to which theturbulence theside wall. Suctionapplied ahead of the model is altered by thecontraction depends on the is much less effective in controlling the boundary incomingturbulence scales, and the total strain layerdevelopment, as the boundary layerrecovers experienced by the fluid as well asthe contrac- rapidlyafter the suction area and responds to the tion ratio and the strain rate. pressure field in a manner similar to thatwithout suction. DissertationAbstracts.

*High-speedAeronautics Iab., NationalAeronauti- *IllinoisInstitute ofTechnology, Chicago, Ill. calEstablishment, Ottawa, Canada

189. Winblade, R. L.: Advanced TransportAir- 187. fWilson, Vernon, E.: DesignStudies of Lam- craft Technology. Airport Forum, vol.10, inar Flow Control (LFC) Wing ConceptsUsing Super- June1980, pp.44-48, 50. plastics Formingand Diffusion Bonding (SPF/DB). FinalReport, NASA CR-159220, Aug. 1978 - A80-44114 Sept.1979, May 1980, 114pp.

41 Various elements of the NASA aircraft energy This difference decreases in the middle streamwise efficiency program are described. Regarding com- instability region, and almost vanishes in the posite structures, the development of three rear crossflow instability region. Compressibil- secondary and threemediumprimary components to ity of the medium reducesN by about 15% in both validate structural and fabrication technology is the front and rear regions, and by about40% in discussed. In laminar flow control, the design of the middle region of the wing. Nonuniformity of advanced airfoils having large regions of super- the medium has large effects especially in the critical flow with features which simplify lami- rear region. narization are considered. Ehphasis is placed on engine performance improvement, directed at devel- *Old Dominion Eniv., Norfolk, Va. oping advanced components to reduce fuel comsump- Grant NSD 1645 tion in current production engines, and engine (Note: NASA CR-3245, Feb. 1980 has the same diagnostics aimed at identifying the sources and title. ) causes of performance deterioration in high-bypass turbofan engines. In addition, the results of propeller aerodynamic and acoustic tests havesub 192. *Floryan, J. M.; and *Saric, W. S.: Wave- stantiated the feasibility of achieving the pro- length Selection and Total Growth of Gortler peller efficiency goal of 80% and confirmed that Vortices. AIAA 13th Fluid and Plasma Dynamics the effect of blade sweep on reducing propeller Conference, Snowmass, Colo., July 14-16, 1980, source noise was 5-6 dB. 18 PP.

*NASA, Transport Aircraft Office, Washington,D.C. AIAA-80-1376 A80-44145#

This paper investigates a wavelength selec- 190. *Malik, M. R.: Transition Prediction Using tion mechanism under ideal and nonideal flow con- Three Dimensional .Stability Analysis. NASA ditions. The conditions of the total streanwise CR-159277; R-SAG6/80-01. June 1980, 31 pp. growth of Grtler vortices generated under ideal and nonideal flow conditions and its effect on N80-26621# the laminar-turbulent transition process is also examined. The stabilizing effects of suctionon Several methods of transition prediction by the total growth of these vortices are analyzed. linear stability analysis are compared. The It is demonstrated that the wavelength selection spectral stability analysis code SALLY is used to mechanism and the total growthof the vortices are analyze flows over laminar flow control wings. It affected by the departures from ideal flow con- is shown that transition by the envelope method ditions. It is shown that under ideal flow con- and a new modified wave packet method are ditions, a wavelength selection mechanism becan comparable in reliability but that the envelope based on the maximum amplification rate of the method is more efficient computationally. disturbances. However, this mechanism is easily affected by the departures from ideal flow. The *Systems and Applied Sciences Corp., Hampton, Va. case of streamwise vorticity in the basic flow is Contract NASI- 15604 analyzed and is shown to affect disturbances through a subharmonic resonance.

191. *El-Hady, N. M.: On the Stability of Three- *Virginia Polytechnic Institute and State Dimensional Compressible Nonparallel Boundary University, Blacksburg, Va. Layers. Presented at AIAA 13th Fluid and Plasma Grant NsG1255 Dynamics Conference, Snowmass,Colo.,, July 14-16, 1980, 15 pp. 193. *-gab, S. A.; and *Nayfeh, A. H.: Effect AIAA-80- 1374 A80-44144# 1374 AIAA-80- of Pressure Gradients on Ggrtler Instability. AIAA 13th Fluid and Plasma Dynamics Conference, Snowmass, Colo., July 14-16, 1980, 26 pp. A compressible linear stability theory is presented for three-dimensional nonuniform bound- AIAA-80-1377 A80-44146# ary layers. The amplitude, phase, and wavenumber equation which govern the motion of the distur- Gortler instability for boundary-layer flows bance are obtained by using the method of multiple over generally curved walls is considered. The scales. Group velocity trajectories are used to full linearized disturbance equations are obtained identify the disturbance growth direction. The in an orthogonal curvilinear coordinate system. A spatial stability theory is applied to the onflow perturbation procedure to account for second-order a laminar flow control supercritical sweptback effects is used to determine the effects of the wing of infinite span. Three different methods displacement thickness and the variation of the are used to calculate the absolute maximum loga- streamline curvature on the neutral stability of rithmic amplitude ratio N. In the front crossflow the Blasius flow. The pressure gradient in the instability region, the method of maximum spatial mean flow is accounted for by solving the nonsim- growth rate predicts large difference incow N ilar boundary-layer equations. Growth rates are pared with the method of fixed wavelength and the obtained for the actual mean flow and the Falkner- method of fixed spanwise component of wavelength. Skan flows. The results demonstrate the strong

42 1-

influence of thepressure gradient and the AIAA-80-1375 A80-41588) nonsimilarityof the basic flow on the stability characteristics. The papercompares several methods of transitionprediction of linearstability analysis. The *VirginiaPolytechnic Institute and State Univer- spectral stability analysis code SALLY is used to sity,Blacksburg, Va. analyzeflows over laminar flow control wings. It Navy supportedresearch. is shown that transition prediction by theenve- Grant NsG- 1255 lope methodand a new rmdified wave packet method are comparable inreliability, but that the envelope method is more efficient computation- 194. *Nayfeh, A. H.; *Reed, H. L.; and **-gab, ally.This is based on theresults which show S. A.: Flow Over Plates With Suction Through that the wave packet method provides N factors PorousStrips. AIAA 13thFluid and Plasma which are atbest as consistent as those of the Dynamics Conference, Snowmass., Colo., July 14-16, envelopemethod; since the wave packet method is 1980, 24 pp. at least 3 times asexpensive as the envelope method, the latter is recommended forengineering AIAA-80-1416 A80-44157# designcalculations.

This paperaddresses the steady, incompres- *Systemsand Applied Sciences Corp., Hampton, Va. sible, two-dimensionalflow past a flat plate **MIT, Cambridge, Mass. withsuction through porous strips. Closed-form Contracts NAS1-15604 and NAS1-15894 solutionsfor each flow quantity are developedin thecontext of linearizedtriple-deck theory using Fouriertransforms. To demonstratethe validity 197. *Philipp, V. M.: Developmentof Natural Dis- of theseclosed-form solutions, we compare the turbances/Perturbationsin a LaminarBoundary wallshear stress andpressure coefficients and Layer.Translation into English from UCh. Zap. thestreanrise velocity profiles from thelinear- (Availableto U.S. Gov't.agencies and their izedtheory with those obtained by thenumerical contractorsonly.) integration of bothinteracting andnonsimilar boundary-layerequations. The agreementbetween AD-BO507610 X81-72147 thelinearized triple-deck and interacting boundary-layerequations is good;however, the *Air ForceSystems Command, Wright-Patterson AFB, nonsimilarboundary layers, which fail to account Ohio for upstreaminfluence, are shown to be in poor agreementwith both interacting boundary layers andthe linearized triple deck. The linearized 198.*Eppler, R.; and**Somers, D. M. : A Computer closed-formsolutions will therefore be veryuse- Program forthe Designand Analysis of Low-Speed fulin future stability calculations. Airfoils. NASA 1M-80210, August 1980,145 pp.

*VirginiaPolytechnic Institute and State Univ., N80-29254# Blacksburg, Va. **Lockheed-Georgia Co., Marietta, Ga. A conformal-mapping method for thedesign of Work supported by ONR and NASA Grant NSG- 1255. airfoils with prescribed velocity-distribution characteristics, apanel method forthe analysis ofthe potential flow about given airfoils, and a 195. *ComptrollerGeneral of the United States: A boundary-layer method havebeen combined. With Look at NASA's Aircraft Energy Efficiency Program. this combinedmethod, airfoilswith prescribed PSAD-80-50, July 28, 1980, 94 pp. boundary-layercharacteristics can be designed andairfoils with prescribed shapes can be ana- N81-26149# lyzed. All three methods are describedbriefly. A FORTRAN IV computerprogram forthe numerical The status of the program,the coordination evaluation of these methods is availablethrough effectiveness between NASA andthe Department of COSMIC. me programand its inputoptions are Defense,the need for periodic reporting to the describedin detail. A completelisting is given Congress on efforts such as ACEE, and NASA's role as anappendix. inaeronautical research anddevelopment were examined. hphasis is placed on the development Note:For a supplement tothis report see #210 in of technologies which would make futuretransport thisbibliography. aircraft up to 50% more fuel efficient than current models. *Stuttgart Univ., West Germany **NASA, LangleyResearch Center, Hampton, Va. *Washingtion, D.C.

199.*Hawkins, W. M.: Liquid Hydrogen - An Cut- 196. *Malik, M. R.; and**Orszag, S. A. :. Compari- standingAlternate Fuel for Transport Aircraft. son--~€Methods forPrediction of Transition by In:Safe and Efficient Management ofEnergy; StabilityAnalysis. AIM Fluidand Plasma Dynam- Proceedingsof the 33rd Annual International Air ics Conference,13th, Snowmass, Colo., July 14-16, SafetySeminar, Christchurch, New Zealand, 1980,7 pp. Sept. 15-18, 1980,(A82-17276). pp.270-295.

43 A82- 17290 Alternatives in the design of laminarflow control (LFC) subsoniccommercial transport air- Liquidhydrogen is proposedas an excellent craft for operation in the 1980's period were alternate aircraft fuel, wing to its worldwide studied.Analyses were conducted to select mis- availability, low cost, ability to be transported sion parameters anddefine optimum aircraft con- and stored without difficulty, and minimum impact figurationalparameters for the selected mission, on theenvironment. NASA compared thecharacter- defined by a passengerpayload of 400 and a design istics andperformance of three aircraft using rangeof 12,038 lan (6500 n mi). The base-line ( 1) synthetic Jet A, (2) liquid methane,and aircraft developed for this mission was usedas a (3)liquid hydrogen. The liquid hydrogen air- vehiclefor the evaluation and development of craft was found to weigh considerably less than alternative LFC systemconcepts. Alternatives in theothers, thereby reducing the take-off gross the areas ofaerodynamics, structures and mater- weight.Every poundof hydrogenproduces ials, LFC system,leading-edge region cleaning, 51,590 BTU's, whereas a poundof Jet A produces andintegration of auxiliarysystems were studied. only18,400 BTU's. Moreover theliquid hydrogen Relative to a similarly-optimizedadvanced tech- aircraftuses the least energy in spite ofaero- nology turbulent transport, the final LFC configu- dynamic disadvantages of the aircraft andhigh ration is approximatelyequal in DOC butprovides energyneeds for liquefaction and the manufactur- decreases of8.2% ingross weight and 2 1.7% in ingprocess. Liquid hydrogen also has a fly- fuel consumption. overnoise level of89 decibels compared to the 94 'decibelsfor the Synjet aircraft. A simple *Lockheed-Georgia Co., Marietta, Ga. systemof laminar flow maintenance using liquid Contract NAS 1- 1463 1 hydrogen is discussed, and severalsafety features of thefuel are noted. 202.Lockheed-Georgia CO., Marietta:Etraluation ofLaminar Flow Control SystemConcepts for 'FlightSafety Foundation, Inc., Arlington,va. "" SubsonicCommercial Transport Aircraft. Summary Rept.Lockheed No.LG80ER0149; NASA CR-159254, 200. *Mask, R. L.: Low Dray Airfoil Design Sept. 1980, 100 pp.

Utilizina"~~ Passive Laminar Flow and COUDled DiffusionControl Techniques. Final Rept., N80-31384# 30 Sept. 1977 - 1 Dec. 1979,Sept. 1980, 84 pp. (ATC-R-91100/9 CR-71, NADC-79119-60). A study vas conducted toevaluate alterna- tivesin the design oflaminar flow control (LFC) AD-A090778 1- N8 12024X suLsoniccommercial transport aircraft for operationin the 1980's period. Analyses were con- A two dimensionalhigh chord Reynolds number ducted to select missionparameters and define passivelaminar airfoil was designedfor optimum aircraftconfigurational parameters for CL = 0.73 at M, = 0.06 and Rec = 4 x lo7 pro- theselected mission, defined by apassenger vidingan extremely high L/D = 240. Thislaminar payloadof 400 anda design range of 12,038 km airfoildesign concept integrates passive laminar (6500 n. mi.). The baselineaircraft developed flowstabilization, by pressuregradient shaping, for this mission was usedas a vehicle for the withactive diffusion control techniques on evaluationand development of alternative LFC sys- theairfoil trailing edge. A discussion of the tem concepts.Alternatives were evaluatedin the airfoildesign concept and thepredicted perfor- areas ofaerodynamics, structures, materials, LFC mance is presented.Full scale Reynolds number systems,leading-edge region cleaning and integra- passivelaminar flow/transition experiments defin- tion of auxiliarysystems. Basedon theseevalua- ing maximum transition Reynolds number and real tions,concepts in each area were selected flowenvironment influence on transition are forfurther development and testing and ultimate presented.Examination of wind tunnelscaling incorporationin the final study aircraft. Rela- influencesand real flow environment effects on tiveto a similarly-optimized advanced technology the ATC/laminar airfoilperformance are discussed turbulenttransport, the final LFC configuration andsummarized fortypical low turbulencetunnels. is approximatelyequal in direct operating cost butprovides decreases of 8.2% ingross weight and *Vought Corp.,Dallas, Texas 21.7% infuel consumption. Contracts N62269-77-C-0442 N62269-79-C-0277 Contract NAS1-14631

(Note:For another form of this work see #I46 in thisbibliography.) 203.Bogdevich, V. G.; Kobets, G. F.; Koziuk, G. S.; Migirenko, G. S.: Mikuta, v. I.; Mironov, B. P.; Novikov, B. G.; Tetianko, V. A.; and 201. *Sturgeon, R. F. : Evaluation of Laminar Flow Shtatnov,Iu. V.: Some QuestionsRelating to the ControlSystem Concepts for Subsonic Commercial Controlof FlowsNear a Wall. (FMTF-Zhurnal ~~~ ~~..~- TransportAircraft. Final Rept. LG~OER-~~;NASA PrikladnoiMekhaniki i TekhnicheskoiFiziki. CR-159253, Sept.1980, 316 pp. Sept.-Oct.1980, pp. 99-109.) Ranslationin Journal ofApplied Mechanics and Technical N80-33394# Physics,vol. 21,no. 5, March 1981, pp. 657-665, 44 refs.

44 A81-46784 (mglish) 206. *Gaster, M.: On Transition to Turbulencein ~81-21061(lhssian) BoundaryLayers. In: Proceedings of the Sympo- sium on "Transitionand Turbulence" in fluids, A review is presented of cavitationflows in Madison,Wisconsin, kt. 13-15, 1980,pp. 95-112 heavy liquids,characteristics of transition of (A82-124381, New York, Academic Press, 1981. laminarto turbulent flows, and laminarization of wall-boundaryflows on permeablesurfaces. The A82- 12443 interaction ofgas bubbles and polymer additions on the structure ofwall-boundary turbulence is Transitionprocesses that occur in boundary examined. layerflows such as those that arise on thesurface of smooth aerofoilsare analyzed by examining theidealized problem of transition in the bound- 204. Levchenko, V. Ya.; andSOlov'ev, A. S.: arylayer of a flat plate at zero incidence to the Interaction of Wave Disturbancesin an Oscillating flow. The type of stability probleminvolved is Boundary Layer.Fluid Dynamics, vol. 15,no. 5, defined,and parallel flows are analyzed. Wave- March1981, pp. 756-760. Translatedfrom packets in a parallel flow and in a growing bound- Izvestiya, Akademii NaukSSSR, Mekhanika Zhidkosti arylayer are discussed,and experimental work on i Gaza, no. 5,pp. 154-158, Sept.-Oct. 1980. theevolution of wave packetsin a laminar boundarylayer ona flat plate is reported. A theoretical analysis is made of theinter- action of wave disturbances of small finite ampli- *National Maritime Institute,Teddington, Middx., tudein a boundary layerin the case when the England velocity distribution contains a periodic compo- nentthat oscillates in time inaccordance with a Grant AF-AFOSR-80-0272 harmonic law. It is shown that it is inprinciple Contract F49620-78-C-0062 possiblefor there to be a four-wavesynchronous (resonance)interaction in a cubicnonlinearity; 207.*Cunnington, G. R., Jr.; and'Parmley, R. T.: equationsare obtained for the amplitudes. Calcu- ..Aerodynamic SurfaceCooling for Laminar Flow Con- lations made to test theeffectiveness of the tro1"forHydrogen-Fueled Subsonic Aircraft. SAE, resonance phenomena have shown thatthe coupling AerospaceCongress and Exposition, Los Angeles, coefficientsare not sufficiently large for the Calif., Oct.13-16, 1980, pp.9 superimposed oscillations to change significantly thenature of the interaction of the waves. SAE-80- 1155 A8 1- 34245

The natureand magnitude of thepotential of 205. *Steers,Louis L.: NaturalLaminar Flow cryogenic-fueledaircraft designs for laminar flow FlightExperiment. In NASA -2172,(N81-19001), control, by use of thesensible heat of thestored pp.135-144, "Advanced Aerodynamicsand Active fuelto cool aerodynamicsurfaces, are explored. Controls."Selected NASA Research, Feb.1981. It is shown thatcooling the boundary layer below Presentedat the 4th Ann. Status Rev. of the NASA adiabaticwall conditions delays turbulent region Aircrafthergy Efficiency (ACEE) Energy Efficient transition andreduces frictional drag, with pre- TransportProgram, Mountain View, Calif., liminarydesign calculations promising, for Oct. 7-9,1980. thecase of liquidhydrogen and nitrogen heat- transferfluid, 20% fuelrequirement reductions in N81-19010# a M 0.85-cruise,400-passenger aircraft on a 12,000 km flight. The coolingsystem entailed is A supercriticalairfoil section was designed a simple,current-technology design which doesnot withfavorable pressure gradients on boththe adverselyaffect safety or normal operationalfac- upperand lower surfaces. Wind tunnel tests were tors. 'It is estimatedthat the fuel weight sav- conductedin the Langley 8 FootTransonic Pressure ings will be greaterthan the added cooling system Tunnel. The outer wing panels of the F- 111 TACT weight,although further, experimental studies are airplane were modifiedto incorporate partial span needed toverify the accuracy ofdrag-reduction test gloveshaving the natural laminar flow predictions. profile.Instrumentation was installedto provide surfacepressure data as well as todetermine *LockheedResearch Labs., Palo Alto, Calif. transitionlocation and boundary layer characteristics. The flightexperiment encompassed 19 flightsconducted with and without transition 208. Brykina, I. G.; Gershbein, E. A.; and fixed at severallocations for wingleading edge Peigin, S. V.: LaminarBoundary Iayer on sweep angleswhich varied from 10 to 26 at Mach Sweptback Wings of Infinite Span at an Angle numbers from 0.80 to 0.85 and altitudesof ofAttack. (Akademiia Nauk SSSR, Izvestiia, 7620 meters and9144 meters. Preliminaryresults Mekhanika Zhidkosti i Gaza, May-June 1980, indicate that a largeportion of the test chord pp.27-39.) Fluid Dynamics, vol. 15,no. 3, experiencedlaminar flow. Nov. 1980, pp.344-354. (Translation.)

'NASA,Hugh L. Dryden FlightResearch Center, A81- 17656 Edwards, Calif.

45 In the present paper, the compressible boun- 211.Padhye, A.: NonparallelStability of Three- darylayer flow on swept wingsof infinitespan is DimensionalFlows. Ph.D. Thesis,Virginia Poly- studiedfor various angles of attack under the technicInstitute and State Univ.,1980, 140 pp. assumptionof an impermeable or BLC wingsurface. (Available from UniversityMicrofilms, Order A first-approximationanalytical solution is No. 8110471.) obtained (also foraxisymmetric flow) by aninte- gral methodof successive approximations. Asymp- N81-26070 totic solutions of theboundary layer equations are obtainedfor large values of the BLC An analysis of linear stability of three parameter. dimensionalboundary layer flows is presented. Both temporal and spatial stabilities are considered. The methodof multiple scales is used to 209.*Harvey, W. D.; *Stainback, P. C.; and accountfor the nonparallelism of the mean flow, **Owen,F. K.: Evaluationof Flow Qualityin Two and to deriveamplitude and wave-number modulation Large NASA Wind Tunnels at RansonicSpeeds. NASA equations. The wavenumber modulationequation is TP1737, Dec. 1980, 76 pp. used to develop a formal method for obtaining neutralstability. The amplitudemodulation equa- N81- 13303# tion is used to develop a transformationrelating thetemporal and spatial stabilities. Inthe case Wind-tunnel testingof low-drag airfoilsand ofthree dimensional flows, the calculations are basictransition studies at transonicspeeds are performed in temporal stability which is then designed to providehigh quality aerodynamic data transformed to be the spatial alongthe direction at highReynolds numbers. This requires that the of groupvelocity. The most amplifieddisturbance flowquality in facilities used for such research at anygiven frequency is oriented almost normal beexcellent. To obtain a betterunderstanding of to thedirection of the potential flow. The cor- thecharacteristics of facility disturbances respondinggroup velocity is directed almost along andidentification of theirsources for possible thedirection of the potential flow. facilitymodification, detailed flow quality measurements were made in two prospective NASA Dissertation Abstracts. wind tunnels. This paperpresents experimental resultsof an extensive andsystematic flow- qualitystudy of thesettling chamber, test sec- 212. *Floryan, J. M.: Stabilityof Boundary-Layer tion, and diffuserin the Langley 8-FootTransonic Flows Over Curved Walls. Ph.D. Thesis , 1980, PressureTunnel (TPT) and the Ames 12-Foot Pres- VirginiaPolytechnic Institute and StateUniv., sure Wind Tunnel (PWT). Resultsindicate that the 175pp. freestream velocity andpressure fluctuation levelsin both facilities are low (<0.1percent) N80-30668 at subsonicspeeds and are so high as to make Avail.:Univ. Microfilms it difficult to conductmeaningful boundary-layer Order No. 8020206 controland transition studies at transonic speeds. The formalanalysis of the Ggrtler-type instability is presented. The boundarylayer *NASA, LangleyResearch Center, Hampton, Va. equationsand the disturbance equations are formu- **COMPLERE, Inc.,Palo Alto, Calif. latedin a general,orthogonal, curvilinear system ofcoordinates constructed from the inviscid flow over a curvedsurface. Effects of the curvature 210.*EppleT, R.; and**Somers, D. M.: A Computer of the wall on theboundary layer flow are ana- Program for the Designand Analysis of Low-Speed lyzedand are shown to be insignificant for the Airfoils, Supplement. NASA TM-81862, Dec.~ 1980, intendedstability analysis. The basicapprox- 30PP. imation for thedisturbance equations is presentedand solved numerically. Previous analyses N81-13921# are discussedand compared with the present one. Results show theimportance of the boundary layer Three new options were incorporatedinto an growthand are in a goodagreement with the exper- existingcomputer program for the design and anal- imentaldata. Effects of suction are introduced ysis of low speedairfoils. Theseoptions permit and are shown to stabilizethe boundary layer. theanalysis of airfoils having variable chord (variablegeometry), a boundarylayer displace- Dissertation Abstracts. ment iteration, and theanalysis of the effectof singleroughness elements. All threeoptions are *VirginiaPolytechnic Institute and State Univ- described in detail and are included in the ersity,Blacksburg, Va. FORTRAN IV computerprogram.

Note: Forthe main report see citation #198 213. *Owen,F. K.: Measurementsof Flow Wality Aug. 'BO inthis bibliography. in the Ames 2 x 2 Ft Transonic Wind Tunnel. AIAA 19th Aerospace SciencesMeeting, St. Louis, Mo., *Stuttgart Univ., Stuttgart, West Germany Jan. 12-15, 1981, 7 pp. **NASA, LangleyResearch Center, Hampton, Va. AIM-81-0156 A81-20636#

46 For decades, wind tunnel testing has been have supercritical airfoil sections; one has conducted in test section environmentswhich have a sweep angle of 23 deg, the other of 35 deg. ” not been adequately documented. However, with Zero-frequency disturbances are used to represent the advent of the energy shortage, the need for cross-flow instability, and disturbances with improved fuel-efficient transports employing the wavenumber vector aligned with the local flow supercritical or LFC airfoils has increased the direction represent traveling-wave instability. awareness of the possible influence of freestream In both cases, the maximum spatial amplification turbulence on advanced experimental testing. This rate is used as a measure of the instability. For has already lead to detailed flow quality measure- the suction, distributions with constant mass flux ments in NASA transonic wind tunnels. The purpose downstream of the starting point are used. The of this paper is to present results of a study in main objective is to determine how the maximum the Ames 2 x 2 ft transonic wind tunnel. amplification rate varies with the magnitude and starting point of the suction. It is found for *Complere, Inc., Palo Alto, Calif. , U.S. Air Force both types of disturbances that the maximum ampli- supported research. fication rate varies almost linearly with the Contract NAS2- 10352 suction magnitude up to at least the point where the amplification rate is halved. Different starting locations for the suction in the first 214. *Thomas, A. S. W. ; and *Cornelius, K. C. : An 4% of the chord were found to affect cross-flow Experimental Investigation of the Flow of a La&- instability, but to have little influence on nar Boundary Layer into a Suction Slot. AIAA 19th traveling-wave instability. Aerospace Sciences Meeting, St. Louis, lo. , Jan. 12-15, 1981, 12 pp. *California Institute of Technology, Jet Propul- sion Lab., Pasadena, Calif. AIAA-81-0194 A81-20665F Contract NAS7- 100

The problem of the flow of a laminar boundary layer into a suction slot has been examined exper- 216. *Sonoda, T.; and *Aihara, Y.: Effects of imentally in a low turbulence water channel. A Pressure Gradients on the Secondary Instability of dimensional analysis is used to determine the Gartier Vortices. AIAA 19th Aerospace Sciences variables that are important to the problem and Meeting, St. Louis, Mo., Jan. 12-15, 1981, 12 pp. these are found to be the slot Reynolds number and a new parameter that is introduced to describe the AIAA-81-0197 A81-20666# mean velocity gradient in the flow above the slot. Measurements are then reported of the characteris- The paper discusses the experimental results tics of the separation region within the slot and on the secondary instability of GGrtler vortices the slot pressure loss. These data show unique in low speed boundary layers under the influence collapse when expressed in terms of these similar- of pressure gradient. It is found that the sec- ity variables and may now be used as a predictive ondary instability in the form of horseshoe type design tool. The flow in the region above the vortices is important to the transition of the slot, in both the upstream and downstream direc- boundary layer. The effects of pressure gradient tions, has also been examined. The upstream flow are observed to appear through a changing of the development can be likened to that of a boundary high shear layer in three-dimensional mean veloc- layer that develops from some displaced effective ity field. Influence of pressure gradient on the origin. The possibility of a Taylor-Goertler upstream region is noticed. rational instability occurring just downstream of the slot has been studied and is not found to be *Tokyo University, Tokyo, Japan critical to the subsequent flow development. Finally, some brief discussion is given to the implications of these findings in the design of 217. *Nastrom, G. D.; **Holdeman, J. D.; and suction slots for Laminar Flow Control ***Davis, R. E.: Cloud Encounter and Particle applications. Density Variabilities from GASP data. Paper presented at AIAA 19th Aerospace Sciences Meeting, *Lockheed-Georgia Co., Marietta, Ga. St. Louis, Mo., Jan. 12-15, 1981, 7 pp. Also, Journal of Aircraft, vol. 19, no. 4. April 1982, pp. 272-277. 215. *Mack, L. M.: Compressible Boundary-Layer Stability Calculations for Sweptback Wings with AIAA-81-0308 A81-20742# Suction. Presented at the 19th AIAA Aerospace Sciences Meeting, St. Louis, Mo., Jan. 12-15, Summary statics and variability studies are 1981, 10 pp. presented for cloud encounter and particle number density data taken as part of the NASA Global AIAA-81-0196 -1-20840R Atmospheric Sampling Program (GASP) aboard commercial Boeing 747 airliners. On the average, cloud The stability of the laminar boundary layers encounter is shown on about 15% of the 52,164 data on two transonic wings of infinite span with dis- samples available, but this value varies with tributed suction is investigated with the compres- season, latitude, synoptic weather situation, and sible, parallel-flow stability theory. Both wings distance from the tropopause. The number density

47 of particles (diameter greater than 3 pm) also 219. *SOmers, Dan M.: NASA Research RzlatecltoI varieswith time and location,and depends on the SailplaneAirfoils. In: Proceedings of 1981 horizontalextent of cloudiness. S.S.A. (SoaringSociety of America)National SoaringConvention, Phoenix, Ariz., Jan. 14-18, Clouds are also ofinterest for proposed 1981, pp. 99-109. (Publishedby the Arizona laminarflow control (LFC) wing aircraft. This Soaring ASSOC. (ASA) 1981.) interest, whichprovided the motivation for this study, is due to some evidencethat the low drag The theoretical methodsand experimental characteristics of LFC wings are lost, albeit facilities at the NASA LangleyResearch Center temporarily,whenever visible clouds are encoun- havebeen employed to conductinvestigations of tered and sometimes incirrus hazes, thereby sailplaneairfoils. The uniqueand powerful capa- influencingthe economic feasibility of LFC. bilities of the Eppler Program havebeen used to designand analyze many airfoils and to smooth *Control Data Corp.,Minneapolis, Minn. several Wortmann airfoils. Wind-tunnel investi- **NASA, Lewis ResearchCenter, Cleveland, Ohio gations of two sailplane airfoils havebeen con- ***NASA, IangleyResearch Center, Hampton, Va. ductedin the Langley low-turbulence pressure tunnel. A procedurefor sailplane performance improvementhas been outlined. 218. *Kong, Fred Y.; and*Schetz, Joseph A.: TurbulentBoundary Layer Over Solidand Porous *NASA, LangleyResearch Center, Hampton, Va. Surfaceswith Small RDughness. Paperpresented at AIAA 19thAerospace Sciences Meeting, St. Louis, Mo., Jan. 12-15, 1981,13 pp. 220. *Wazzan, A. R.; *Gazley, C., Jr.; and*Smith, A. M. 0.: The H-R Method for PredictingTrans~i- AIAA-81-0418 A81-20820# -tion. I?AND/F6581, Jan. 1981, 14 pp.

Experimentalstudies were conducted to obtain N81-25328# directmeasurements of skin friction, mean velocityprofiles, axial andnormal turbulence A shortcut method, the H-% method, for intensityprofiles, andReynolds stress profiles predicting transition in a wide class ofboundary in theboundary layer on a large-diameter,axi- layerflows, including the effects of pressure symmetric body with a solid, smooth surface, a gradient,surface heat transfer, and suction is sandpaper-roughened,solid surface and a porous, described. Here H and 5, are the bodyshape sintered metal surfacein the same nominalrough- factor and theReynolds number, based on distance nessrange as thesandpaper. The roughnessvalues x measured in the directionof the flow, were inthe low rangejust above what is normally respectively. The method is extremely simple to considered"hydraulically smooth".Measurements useand a good substitute to the well known but were taken at fourdifferent axial locations rathercomplicated e to the9th power method. (exceptfor the porous surface, for whichmeasure- ments were made only at the last station) andtwo *CaliforniaUniv., Ws Angeles,Calif. different freestream velocitiescorresponding to dynamic pressuresof 12.7and 17.8 cm H20, which gives a ReL range of 4.96 X lo6 to 6.11 X lo6. 221. *Orszag, S. A.: Advanced StabilityAnalysis For the Law ofthe Wall, the Defect Law, and the for Laminar Flow Control.Final Rept. CHI-43; turbulencequantities, good agreementexists NASA CR-165661, Feb.1981, 126 pp. betweenthe present results andthose from well- establishedstudies for solid, smooth surfaces. N81-17381# The sandpaper-roughened wall tests showed an increasein local skinfriction and a slight shift Five classes of problems are addressed: in the log region of the Wall Law, as well as an ( 1)the extension of the SALLY stability analysis increasein turbulence quantities. These results code to thefull eighth order compressible stabil- were inaccord with classical results for uniform ityequations for three dimensional boundary sandgrain roughness. For theporous wall case, layer; (2) a comparisonof methods forprediction a higherincrease in local skin friction and oftransition using SALLY forincompressible marked downward shift ofthe log region of the flows;(3) a studyof instability and transition Wall Law were observed. All theturbulence quan- inrotating disk flows in which the effects tities also showed a definiteincrease in magni- ofCoriolis forces andstreamline curvature are tudes, which were greater thanthose observed from included;(4) a new linearthree dimensional thesandpaper-roughened wall. These resultsindi- instability mechanism thatpredicts Reynolds num- cate that the porosity andnon-uniformity of the bersfor transition to turbulencein planar shear poroussurface influences the turbulent boundary flowsin good agreementwith experiment; and (5) a layer mre stronglythan a uniformlysand- study of thestability of finiteamplitude distur- roughened,solid surface in the same nominal bancesin axisymmetric pipe flow showing the sta- range. bility of this flow to all nonlinearaxisymmetric disturbances. *VirginiaPolytechnic Inst. and State Univ., Blacksburg, Va. *CambridgeHydrodynamics, Inc., Mass. Work supported by NASA, LaRC. Contract NASI- 15894

48 222. *Jagger, D. H.: Design Possibilitiesfor 224. *Jenkins, M. W. M.: In-FlightResearch - ImprovedFuel Efficiency of Civil Transport At Low Cost.Lockheed Horizons, Spring 1981, ., , ~L Aircraft.In: SymposiumEnergy on Management and pp. 32-39. Its Impact on Avionics,bndon, March 19,1981, (A82-20513),Royal AeronauticalSociety. 9 pp. A81-29208

A82-20514 An overview is presented of a flight test program in which amanned, jet-poweredsailplane The possible application and potential bene- hasbeen used inconjunction with several remotely fits of varioustechnical advances in aerody- controlled0.3-scale research vehicles for namics,structures, and propulsion for the reduc- advancedaerodynamics technology research. Among tion of fuel usage in future Airbus aircraft are theconcerns of the programhave been the effects discussed.In particular, technical comparisons ofwing spanwise blowing, laminar flow control by andtradeoffs in terms of fuel economy are con- slot-suction methods,leading-edge insect strikes, sidered for a hypothetical medium-range project vortexdiffusers, airframe noise, command augmen- aircraft of the1980's. Improvements infuel used tation, and fiber-opticflight controls. A perpassenger at 1,000 n.m. rangeover two succes- description is alsogiven of thefully integrated sive periods of 20 yearsare estimated. A break- groundmonitoring facilities at which test air- down of theobjectives, time-scales, and costsof crafttelemetry is gathered,reduced, and various parts of thecurrent NASA Aircraft mergy analyzed. Efficiency Program is alsogiven. This features suchimprovement aspropulsion/aerodynamic inte- *Lockheed-Georgia Co., Marietta, Ga. grationwinglets, the use of advanced composite materials, dragcleanup, structural-duct integration, minimum suction-naturallaminar flow, reduc- 225.*Holmes, Bruce J.; and *Croom, Cynthia C.: tion ofengine performance losses, and active con- AerodynamicDesign Data for a Cruise-Matched High trolsfor load alleviation. PerformanceSingle mgine Airplane. Presented at theBusiness Aircraft Meeting and Exposition, Wichita,Kansas, April 7-10, 1981, 12 pp.

SAE-8 1- 0625 A8 1-42779 223. *Demetriades, A.: Roughness Effects on Boundary-Layer Transition in a NozzleThroat. Designdata are presented for a class of AIAA Journal,vol 19, no. 3, March 1981, high-performancesingle-engine business air- pp.282-289. planes. The designobjectives include a cruise speed of 300 knots, a cruisealtitude of10,700 m A IAA -81-405 7 A81-2551 AIAA-81-4057 l# (35,000 ft), a cruisepayload of six passengers (including crewand baggage), and a nc-reserves A boundary-layertransition study was carried cruiserange of 1300 n.mi. Two unconventional outin the throat region of the DeLaval nozzle of aerodynamictechologies were evaluated:the indi- a supersonic wind tunnel. The study was motivated vidual andcombined effects ofcruise-matched wing equally by theneed to find thresholds for laminar loading andof a naturallaminar flow airfoil were boundary-layerflow in the tunnel walls when analyzed. The tradeoffdata presented illustrate roughness is present and by thedesire to simulate theranges of wing geometries,propulsion require- transition on roughenedblunt bodies in supersonic ments,airplane weights, andaerodynamic charac- andhypersonic flow. Detailed inviscid and vis- teristics which arenecessary to meet thedesign cousflow measurements were donefrom the low sub- objectives. Very largedesign and performance sonicto the supersonic regions of thenozzle improvements resulted fromuse of the aerodynamic throat. The roughness was caused by attaching technologiesevaluated. It is shown thatthe distributedroughness overlays on thenozzle sur- potentialexists for achieving more than 200- face.Transition, detected by hot-film ane- percentgreater fuel efficiency than is achieved mometers, was found to move upstream as theflow by currentairplanes capable of similarcruise Reynolds number and/orthe roughness height speeds,payloads, and ranges. increased.Cast in the coordinates of some of the empiricalblunt-body transition correlations cur- *NASA, LangleyResearch Center, Hampton, Va. rentlyin use, the present transition data agree withthe available blunt-body data when the non- dimensionalroughness exceeds unity and support 226. *Papenfuss, H.-D.; and*Niehuis, R.: theconcept of a constantroughness Reynolds nun- Grenzschichteffekte 2. Ordnung heider berfor transition in that regime. At the lower kompressiblenStromung mit starkem Absaugen. roughnessheights, the results show thatthe tran- __..(Boundary-Layer Effects of the Second Order sition Bynolds number departs from the aforemen- in a Compressible Flow with Hard Suction. tionedcorrelations andapproaches a limitinsen- DeutscheGesellschaft fkLuft- und Raumfahrt, sitive to roughness but characteristic of the Jahrestagung,hchen, West Germany, May 11-14, experimentalfacility. 1981, 19 pp. Paper 81-018. (In German.)

*Montana State Univ., Bozeman, Mont. A81-47571# Contract F04701-77-C-0113

49 An approach involving suction from the wall speedwind tunnel using hot-wire anemometry. can be used to reducedrag. The effects of sue Tests were conductedon the smooth plate andwith tion are related to a displacementof the separa- two sandpapercoverings, one with Rek = 15and tionpoint and the laminarization of theboundary a coarser sandpaperwith Rek = 150. Themean layer. Up to now, this approachhas been rarely flow measurementsindicated Blasius profiles for used in practical applicationsbecause of techni- the smooth plate andwith the finer sandpaper. cal difficulties. The consideredinvestigation is With the coarser sandpaper, the profile was best concernedwith hard suction. In increasingsuc- approximated by a Blasius profile at the early tionintensity, the limits ofthe validity of the stationsbut then progressed toward a turbulent Prandtlboundary layer concept are approached. profile. The finersandpaper had only very minor Particular attention is given to second-order effectson the disturbance profiles. For the boundary-layereffects, taking into account the coarser sandpaper,the departure of the mean pro- effects of displacement,longitudinal and trans- files from Blasiuscould be identified with dis- versal curvature,and external rotation. The turbanceamplitudes about 10% ofthe mean values. laminarflow around planar and axisymmetrical A studyof disturbance spectra forthis case shows bodies is studied,taking into account compres- largestamplitudes and amplifications at frequen- siblefluids. Second-order boundary-layer theory cies well below theBlasius neutral curve. providesthe result that curvature and rotation effects disappear for the limiting case ofhard *Case Western Reserve Univ.,Cleveland, Ohio suction. Only thedisplacement effect remains. Work supported by AFOSR. It is pointedout that solely the quantities of frictionlessdisplacement flow are neededfor calculatingthe wall gradients ofsecond-order 229.*Harvey. W. D.; and'Bobbitt, P. J.: -Some boundary-layerflow. Anomalies Between Wind Tunneland FlightTransi- tionResults. Paper presented at AIAA 14thFluid 'Bochum, Ruhr-Universitat, Bochum, West Germany andPlasma Dynamics Conference,Palo Alto, Calif., June 23-25, 1981,18 pp.

227. *Creel, Theodore R., Jr.; and*Beckwith, AIAA-81-1225 A8 1-38089# Ivan E. (inventors): A Rectangular Rod-Wall Sound Shield,Patent Application. Filed May 28, 1981, A reviewof environmental disturbance influ- 12 pp. NASA-Case-LAR-12883-1,U.S. Patent enceand boundary layer transition measurements on Application-SN-267935. a large collectionof reference sharp cone tests in wind tunnelsand of recent transonic-supersonic N81-29138# coneflight results have previously demonstrated the dominanceof free-stream disturbance level on A test section for a supersonic or hypersonic the transition process fromthe beginning to end. windtunnel is described. The section is shielded Variationof the ratio oftransition Reynolds from thenoise normally radiated by theturbulent number at onset-to-endwith Mach number hasbeen tunnel wall boundarylayer. A vacuum plenum shown to be consistentlydifferent between flight surroundsspaced rod elements making up the test and wind tunnels.Previous correlations of the chamber. Some of the boundary layer formedalong endof transition with disturbance level give good therod elements during a test is thereby resultsfor flight and large number oftunnels; extracted to delaythe tendency of the rod bound- however,anomalies occur for similar correlation ary layers to become turbulent. Novel rod based on transitiononset. Present cone results constructioninvolves bending. Each rod is bent with a tunnelsonic throat reduced the disturbance prior to machining,providing a flat segmenton level by an orderof magnitude with transition eachrod for connection with the flat entrance valuescomparable to flight. fairing. Rods and fairingare secured to provide a test chamber incline on theorder of 1 degout- *NASA, LangleyResearch Center, Hampton, Va. ward from the noise shield centerline to produce up to a 65% reduction of the root-mean-square (rms) pressureover previously employedwind tun- 230.*Malik, M. R.: and**Orszag, S. A.: Effi- nel test sections at equivalentReynolds numbers. cientComputation of the Stability of Three- Dimensional Compressible Boundary Layers.'AIAA .. . .- " *NASA, LangleyResearch Center, Hampton, Va. 14thFluid and Plasma Dynamics Conference,Palo Alto, Calif.,June 23-25, 1981, 14 pp.

228.*Reshotko, E.; and*Leventhal, L.: prelimi- AIAA-8 1- 1277 A81-38113# naryExperimental Study of Disturbances in a LaminarBoundary-Layer Due toDistributed Surface Methods forthe computer analysis of the sta- .. .. "" Roughness. AIAA 14thFluid- and Plasma Dynamics bility ofthree-dimensional compressible boundary Conference,Palo Alto, Calif.,June 23-25, 1981, layers are discussedand the user-oriented Com- 12 PP. pressibleStability Analysis (COSAL) computer code is described. The COS= codeuses a matrix AIAA-8 1- 1224 finite-difference method for local eigenvalue solution when a good guessfor the eigenvalue is Mean flowand disturbance measurements have available and is significantly more computation- been made on a flat plate model in the CWRU low ally efficient than the commonly usedinitial-

50 h-" valueapproach. The localeigenvalue search pro- 233. *Paaye, A. R.; and*Nayfeh, A. H.: Nonpar- _. cedurealso results ineigenfunctions and, at i- allelStability ofThree-Dimensional Flows. AIM little extra work,group velocities. A globally 14thFluid and Plasma Dynamics Conference,Palo convergenteigenvalue procedure is alsodeveloped Alto, Calif., -ne 23-25, 1981, 12 pp. which may be used when no guessfor the eigenvalue is available. The globalproblem is formulatedin AIAA-8 1- 128 1 A81-39017X such a way that no unstablespurious rmdesappear so that the method is suitable for use in a black- The linear stability ofthree-dimensional box stability code. Sample stabilitycalculations incompressible,isothermal, nonparallel boundary- are presentedfor the boundary layer profiles of layerflows has been investigated. The method of an LFC swept wing. multiple scales is usedto derive the partial- differentialequations that describe the spatial *Systemsand Applied Sciences Corp., Hampton, Va. modulationsof the amplitude, phase and wavenumber **Mass. Institute ofTechnology, Cambridge, Mass. ofa disturbance. Group velocitiesare used to Contracts NAS1-15604;NAS1-15894; and NASI-16237 determinethe disturbance growth direction. The envelope method is used to calculate the logarithmic amplitudegrowth rate N. The theory is 231. *El-Hady, N. M.; and *Verma, A. K.: Growth appliedto the flows over a swept-backtapered of Goertler Vorticesin Compressible Boundary wingwith boundary-layer suction. Results of such LayersAlong Curved Surfaces. Paper presented at analysisfor the X-21 wing are discussed. It is AIAA 14thFluid and Plasma Dynamics Conference, found that the nonparallel effects for this wing PaloAlto, Calif., June 23-25, 1981, 15 pp. aresubstantial.

AI&-8 1- 1278 *VirginiaPolytechnic Institute and State Univ., Blacksburg, Va. The instability of thelaminar compressible boundary layerflows along concave surfaces is investigated. The linearizeddisturbance equa- 234. *Somers, Dan M.: Designand Experimental tionsfor the three-dimensional, counter-rotating, Resultsfor a Natural-Laminar-Flow Airfoilfor longitudinaltype vortices in two-dimensional GeneralAviation Applications. NASA Tp- 1861, boundary layers are presentedin an orthogonal June1981, 104 pp. curvilinearsystem of coordinates. The basic approximation of thedisturbance equations, that N81-24022# includesthe effect of the growth of the boundary layer, is consideredand solved numerically. The A natural-laminar-flowairfoil for general effect of compressibility on the critical stabil- aviationapplications, the NLF(1)-0416, was itylimit, growth rates, andamplitude ratios of designedand analyzed theoretically and verified the vortices is evaluatedfor a range of Mach experimentallyin the Langley Low-TurbulencePres- numbers from 0 to 5. sureTunnel. The basicobjective ofcombining the high maximum lift of the NASA low-speed airfoils *Old Dominion University,Norfolk, Va. withthe low cruisedrag of the NACA 6-seriesair- Grant NSG- 1645 foils was achieved. The safetyrequirement that the maximum lift coefficient not be significantly affectedwith transition fixed near the leading 232.*Reed, H. L.; and*Nayfeh, A. H.: Stability edge was also met.Comparisons of thetheoretical of FlowOver Plateswith Porous Suction Strips. andexperimental results show excellentagreement. Paperpresented at AIAA 14thFluid and Plasma Comparisonswith other airfoils, both laminar flow Dynamics Conference at PaloAlto, Calif., June 23- andturbulent flow, confirm the achievement of the 25,1981, 15 pp. basicobjective.

AIAA-8 1- 1280 A81-40049# *NASA, LangleyResearch Center, Hampton, Va.

Thispaper addresses the stability of two- dimensional,incompressible boundary-layer flow 235. *Somers, Dan M.: Designand Experimental overplates with suction through porous strips. Resultsfor a Flapped Natural-Laminar-Flow Airfoil The mean flow is calculatedusing linearized forGeneral Aviation Applications. NASA TP-1865, triple-deck,closed-form solutions. The stability June1981, 122 pp. results ofthe triple-deck theory are shown to be in good agreementwith those of the interacting Thisreport is FEDD (For Early Domestic Dissemina- boundarylayers. %en different configurations of tion).Available from NASA Industrial Applica- number, spacing,and mass flow rate throughsuch tionsCenters only to U.S. Requestors. porousstrips are analyzed and compared with non- similar uniform-suction stability results from the A flappednatural-laminar-flow airfoil for pointof view of applicability to laminar flow generalaviation applications, the NLF(1)-0215F, control. hasbeen designed and analyzed theoretically and verifiedexperimentally in the Langley Low- *VirginiaPolytechnic Institute and State Univer- TurbulencePressure Tunnel. The basicobjective sity,Blacksburg, Va. ofcombining the high maximum lift of the NASA Grant NSG- 1255 lorspeed airfoils with the low cruisedrag of

51 the NACA 6-seriesairfoils has been achieved. The 238.*Nayfeh, A. H.: Effectof Streamwise Vorti- safety requirement that the maximum lift coef fi- ces on Tollmien-Schlichting Waves. Journal of cient not be significantly affected with transi- FluidMechanics, vol. 107, June 1981, pp.441-453. tionfixed near the leading edge has also been met. Comparisons of thetheoretical and experi- A81-39764# mentalresults show generally good agreement. The methodof multiple scales is used to *NASA, LangleyResearch Center, Hampton, Va. determine a first-orderuniform expansion for the effect of counter-rotatingsteady streamwise vortices in growingboundary layers on oblique 236. *Piatt, M.: An ExperimentalInvestigation Tollmien-Schlichting waves. The results show that of a LargeDelta P Settling Chamber for a suchvortices have a strongtendency to amplify SupersonicPilot pliet !Tunnel. Final Rept. No. obliqueTollmien-Schlichting waves having a span- R-SAG03/81-03, NASA CR-3436, June1981, 81 pp. wise wavelengththat is twicethe wavelength of thevortices. An analyticalexpression is derived N81-24112# forthe growth rates of these waves.These expo- nential growth ratesincrease linearly with Themean streamwiseflow distributions and increasingamplitudes of the vortices. Numerical turhulencelevels across the chamber were measured resultsare presented. They suggestthat this with a hot wire anemometerdownstream of a series mechanism may dominate the instability. ofporous Rigimesh plates which were shown to be aneffective means ofreducing the chamberacous- *VirginiaPolytechnic Institute and State Univ., tic disturbancelevels due toupstream pipe and Blacksburg, Va. valvesystems. Tests made withvarious types of Grant NSG 1255 flowconditioners downstream of the porous plates Also Navy supported. showed that a series of screens was the most effective means of achievingthe objective of a uniform mean flow distributionwith reduced vor- 239.*Pfenninger, W.: Programof Research in ticity levels downstreamof theporous components. Laminar Flow Controlin the JIAFS at NASA Langley Frequency spectraobtained across the series of ResearchCenter. Status Report, 1 Jan. - 30 June screens shows thatthey reduce vorticity over a 1981. NASA CR-164843, July 30, 1981, 15 pp. widefrequency range for several different initial upstreamvorticity conditions. Improvements in N81-32121# themechanical installation of theporous plates anddamping screens and the use of porous plates At highlength Reynolds numbers, the perfor- with more uniformporosity should reduce the free- mance of a low dragsuction LFC airplane is essen- stream velocity fluctuations to the minimum acous- tially controlled by theinduced drag and the tur- tic levelsof about 0.5 percent. bulencefriction drag of thenonlaminarized area. The questionthen arises as to how the airplane *Systemsand Applied Sciences Corp., Hampton, Va. Contract NASl-16096 cruise lift to drag ratio increases (')cruise withincreasing extent of laminar flow 237. *McKinney, Marion 0.; and*Scheiman, James: Olam,/Ototal (0 = airplanewetted area). In Evaluation ofTurbulence Reduction Devices for the particular,the question arises as to the air- Langley8-Foot Transonic Pressure Tunnel. NASA planeperformance in the optimum casewith all lT4-81792, June1981, 30 pp. laminarflow over the airplane wetted area. Designapproaches of all laminarflaw LFC N81-24114# airplanes which optimizethe airplane range

Model tests were made of devicesfor reducing R = qov (r;) H ln(Wo/WE) areconsidered. turbulencein the Langley 8-Foot Transonic Pres- sureTunnel to permit laminar flow airfoil tests. *GeorgeWashington Univ., Wash., D.C. The test model consistedof a cooler,turning Grant NsG 1585 vanes,and settling chamber(immediately upstream ofthe contraction) in which variouscombinations of screensand honeycomb were tested. Conven- 240. *Mangiarotty, R. A.: Effect ofEngine Noise tional hot wires were used to measure the axial on Aircraft Wing LaminarBoundary-Layer Stability. and lateralturbulence reduction for the different Journal of theAcoustical Society of America, turbulencereduction devices. The finalconfigu- vol. 70, no. 1, July 1981,pp. 98-109. rationchosen consisted of a honeycomb followed by fivescreens. Results are presented herein to A81-41255 document thisselection. High-intensityacoustical disturbances can *NASA, LangleyResearch Center, Hampton, Va. causetransition of controlledlaminar flow. An

52 a-r investigation was made to determinewhether main are obtainedfor the actual meanflowand compared propulsionengines installed on an aircraft wing with thosefor the Blasius flow and theFalkner- F' wouldcause excessive transition of laminar to Skanflows. The resultsdemonstrate the strong turbulentflow. A method was developedfor ana- influenceof the pressure gradient and the lyzingthe influence of noise on the stability of nonsimilarity of the basic flow on the stability a controlledlaminar boundary layer, based upon characteristics. theTollmien-Schlichting traveling wave solution ofthe Orr-Sommerfeld equationand some windtun- *VirginiaPolytechnic Institute and State Univer- nelexperimental data. It is concludedthat wing- sity,Blacksburg, Va. mounted,high-bypass-ratio engines with sufficient NsD1255, Navy supportedresearch. acoustictreatment for controlling turbomachinery noise would notcause excessive loss ofwing laminarflow. Additional analytical and experimental 243. *Scheiman, James: Considerationsfor the work is needed,however, to improve theaccuracy Installation of Honeycomb andScreens to Reduce ". ~- ~ """~~ ofengine nearfield noise prediction, and theneed Wind-Tunnel Turbulence. NASA "4-81868, Aug. 1981, to improve theproposed model to accountfor the 53 PP. acoustictransfer function for predicting transition. N81-29137#

*The meing Commercial Airplane Co., Seattle, Tests were conducted on a half-scalemodel Wash. representing a 0.914-111 (3.0-ft.)square stream tube of theflow through the fourth corner and settling chamber of theLangley 8-Foot Transonic 241. *Scheiman,James; and *Brooks, J. D.: PressureTunnel. The model includedthe finned-

parison of Experimental~ and Theoretical Turbulence tube cooler, 45O turningvanes, and the turbu- ".Reduction from Screens, Honeycomb,.. and Honeycomb- lencereduction screens and honeycomb, which were ScreenCombinations. Journal of Aircraft, thesubject of the tests. Hot-wire measurements vol. 18, no. 8, Aug. 1981,pp. 638-643. ofthe turbulence reduction for various combinations of screensand honeycomb were made at vari- ousduct speeds. Of thefour sizes of honeycomb cells tested, none were found to have a supe- A 1/2-scale model of a portionof the NASA rior performanceadvantage. The effectivenessof Langley8-Ft. Transonic Pressure Tunnel was used screens and honeycomb in reducingturbulence is to conduct some turbulencereduction research. greatly affected by relatively minor physical The experimentalresults are correlatedwith vari- damage; therefore, extreme care must beexercised oustheories. Screens alone reduce axial turbu- in installing andmaintaining honeycomb or screens lence more than lateral turbulence,whereas honey- ifthe turbulence reduction performance is to be comb alonereduces lateral turbulence mre than maintained. axialturbulence. Because of this difference, thephysical mechanism fordecreasing turbulence *NASA, LangleyResearch Center, Hampton, va. forscreens and honeycomb must be completelydif- ferent. Honeycomb with a downstreamscreen is an excellentcombination for reducing turbulence. 244. *Campbell,Richard L.: Computer Analysisof Flow PerturbationsGenerated-6; Placement of Choke *NASA, LangleyResearch Center, Hampton, Va. Bumps in a Wind Tunnel. NASA TP-1892, Aug. 1981, (Note: See citation #265, NASA TP1958,for a 42PP. longerand more completeform of this article.) N81-30088#

242. *%gab, S. A.; and*Nayfeh, A. H.: Ggrtler An inviscidanalytical study has been con- Instability.Physics of Fluids, vol. 24, no. 8, ducted to determinethe upstream flow perturba- Aug. 1981,pp. 1405-1417. tionscaused by placingchoke bumps in a wind A81-44527 tunnel. A computerprogram based on the stream- tube curvature method was used to calculate the Gb'rtler instabilityfor boundary-layer flows resultingflow fields for a nominalfree-stream overgenerally curved walls is considered. The Mach number rangeof 0.6 to 0.9. The choke bump fulllinearized disturbance equations are obtained geometry was also varied to investigate the effect in anorthogonal curvilinear coordinate system. A of bump shape on thedisturbance produced. perturbationprocedure to accountfor second-order Resultsfrom the study indicate that a regionof effects is used to determinethe effects of the significantvariation from thefree-stream condi- displacementthickness and the variation of the tionexists upstream of the throat of thetunnel. streamlinecurvature on the neutral stability of "he extent of thedisturbance region was, as a theBlasius flow. The pressuregradient in the rule,dependent on Mach number andthe geometry of mean flow is accountedfor by solving the non- the choke bump. Ingeneral, the upstream distur- similarboundary-layer equations. Growth rates bancedistance decreased for increasing nominal

53 free-stream Mach number and for decreasing length- application to commercial transport aircraft. to-heightratio of the bump. A polynomial-curve Earlier work has shown that an LFC systemgreatly choke bump usuallyproduced less ofa disturbance reducesboth aircraft fuel use and operating cost. thandid a circular-arc bump, andgoing toan axi- Ongoing research studies described in these papers symmetricconfiguration (modeling choke bumps on compliment the major strides being made by indus- all thetunnel walls) generallyresulted in a tryairframe manufacturers (under NASA sponsor- lower disturbancethan with the corresponding two- ship) in LFC structures and materials and in the dimensionalcase. demonstrationof flight systems. Research and technology developments discussed herein include , *NASA, LangleyFesearch Center, Hampton, Va. for example,fundamental studies of improved ana- lyticaltechniques in boundary-layer stability prediction and a greatly expandedexperimental 245.*Montoya, L. C.; *Steers, L. L.; data base characterized by detailedtransonic 'Christopher, D.; and 'Trujillo, B.: F-11 1 TACT wind-tunnelmeasurements on supercritical NaturalLaminar Flow Glove FlightResults. Pre- airfoils. sented at the5th Annual Status Review of the NASA Aircraftmergy Efficiency (ACEE) Transport *NASA, LangleyFesearch Center, Hampton, Va. Program held at Dryden FlightResearch Center, Edwards, Calif.,Sept. 14-15, 1981. NASA -2208, Dec. 1981, pp.11-20. 247. Harvey, W. D.; andPride, J. D., Jr.: The NASA Laminar Flow ControlAirfoil meriment. N82-71010 Presentedat a Conferenceheld at Dryden Flight ResearchCenter, Sept. 17-18 , 1981. Pages 1-42 in Thisreport is FEDD (ForEarly Domestic Dissemina- Laminar Flow Control, NASA CP-2218, March 1982. tion).Available from NASA Industrial Applica- tionsCenters only to U.S. Requestors. N82-20150#

The objective of theexperiment was to The designand construction ofan advanced evaluatethe extent of naturallaminar flow that swept supercriticalairfoil for commercial air- could be achievedwith consistency in a real craft to be tested in a transonic wind tunnel is flight environment at chordReynolds numbers in described. The swept LFC airfoil was designedfor the rangeof 30 X lo6. The experimentconsisted agiven thickness ratio and liftcoefficient, with of 19 flightsconducted on the F-111 TACT airplane emphasisplaced on high critical Mach number with havinga NLF airfoilglove section. The section shock-freeflow. It is compatiblewith satisfac- consisted of a supercritical airfoil providing tory low speedand buffeting characteristics and favorablepressure gradients over extensive por- minimizingthe suction laminarization. Further tions of theupper and lower surfaces of the emphasis was placed on achievingshock-free flow wing.Boundary-layer measurements were obtained over a widerange of off-design conditions includ- overa range ofwing-leading-edge sweep angles ingtrailing edge flapcontrol. The requirements at Mach numbersfrom 0 -80 to 0.85. Data were anddesign of the suction system and modifications obtainedfor natural transition and for a rangeof to theLangley 8-Foot Transonic Pressure Tunnel is forcedtransition locations over the test airfoil. brieflydescribed. Contouring of nonporous test sectionwalls for free air simulation andflow *NASA, Dryden FlightResearch Center, Edwards, quality improvements is included. Calif.

248. *Applin,Zachary T.: Status of NASA Advanced 246. maddalon, Dal V., (Editor): Laminar Flow LFC AirfoilHigh-Lift Study. Presented at a Con- Control - 1981 Researchand Technology Studies. ferenceheld at Dryden FlightResearch Center, NASA CP2218, March 1982, 135 pp.Proceedings Edwards, Calif.,Sept. 17-18,1981. Pages 43-62 of a Conferenceheld at Dryden FlightFesearch in Laminar Flow Control, NASA CP-2218, March 1982. Center,Edwards, Calif. , Sept. 17-18,1981. N82-20151# N82-20149 The designof a high-lift system for the NASA ThisConference hrblication contains papers advanced LFC airfoil designed by Pfenninger is presented at theOral Status -viewof the NASA described. The high-liftsystem consists ofboth Aircraft Energy Efficiency ( ACEE) Laminar Flow leading-and trailing-edge flaps. A 3-meter semi- Control (LFC) Program heldat the Dryden Flight span,1-meter chord wing model usingthe above ResearchCenter in Edwards, Californiaon airfoil and high-liftsystem is underconstruc- September 17- 18, 1981. Laminarflow control tech- tion and will be tested in the NASA Langley nologyhas undergone tremendous progress in recent 4- by 7-Meter Tunnel.This mdel will have two yearsas focused research efforts in structures, separatefull-span leading-edge flaps (0.10~ and materials,aerodynamics, and systems have begun to 0.12~)and one full-span trailing-edge flap payoff. This work,conducted under the NASA Air- (0.25~). The performanceof this high-lift sys- craft Energy Efficiency Laminar Flow ControlPro- tem was predicted by the NASA two-dimensional gram, was begun in 1976. The objective is to dem- viscousmulticomponent airfoil program.This onstratepractical, reliable, LFC technologyfor program was alsoused to predict the characteris-

54 tics of the LFC airfoil8 developed by the Douglas matesof cloud encounter probability are presented -@'Aircraft Company andLockheed-Georgia Aircraft forfour airline routes, and conclusionsare pre- Company. sented as to the best altitudes for cloudavoid- ance in extratropical and tropical latitudes. *NASA, LangleyResearch Center, Hampton, Va.

251. *Wilson, V. E.: SPF/DB TitaniumConcepts for 249. 'Reynolds, G. A,: *Saric, W. S.; *Reed, StructuralEfficiencp Presented at a Conference H. L.; and*Nayfeh, A. H.: Stability ofBoundary held at Dryden FlightResearch Center, Edwards,

~..Layers"" With-Porous Suction Strips: Experiment Calif.,Sept. 17-18,1981. Pages 95-110 in andTheory. Presented at a Conferenceheld at Laminar Flow Control, NASA CF2218, March 1982. Dryden FlLghtResearch Center, Edwards, Calif. , Sept. 17-18, 1981.Pages 63-74 in Laminar Flow N82-20154# Control, NASA -2218, March1982. Illustrations for a presentationdemonstrat- N82-20152# ingsuperplastic forming-diffusion bonding titaniumporous panels are presented.Fabrication Low-turbulencetunnel experiments on the sta- phases,sandwich panels, load bearing qualities, bility and transition of 2-D boundarylayers on microstructure,and panel surface after finishing flat plates with andwithout suction are are illustrated. described. A number ofgeneral suction cases are discussed. Test results showed thatthe maximum 'Rockwell International Corp., Los Angeles,Calif. stabilization occurred when the suction wasmoved toward the Branch I neutralpoint. An analytical study of thestability oftwo-dimensional, incom 252. *Williams, Neil R.: SPF/DB Titanium LFC pressibleboundary-layer flows over plates with PorousPanel Concept. Presented at a Conference suctionthrough porous strips was performed. The heldat Dryden FlightResearch Center, Edwards, mean flow was calculatedusing linearized triple- Calif.,Sept. 17-18, 1981.Pages 111-138 in deck,closed-form solutions. The stability Laminar Flow Control, NASA CP-2218, March 1982. results of thetriple-deck theory are shown to be in good agreementwith those of theinteract- N82-20155# ing boundary layers. An analyticaloptimization scheme forthe suction configuration was Illustrations for a presentation on super- developed.Numerical calculations wereperformed plasticforming/diffusion bonding titanium design correspondingto the experimental configurations. conceptsare presented. Sandwich skinpanels with In eachcase, the theory correctly predicts the hatsection, semicircular corrugation, sine wave, experimentalresults. and trusscores are shown. The fabricationof wingpanels is illustrated, and applicationsto 'VirginiaFolytechnic Institute and State Univ., thedesign of advancedvariable sweep bombers Blacksburg, Va. summarized. ONR Contract N00014-75-C-0381 Grants NSG 1608 and NSG 1255 *McDonnell-DouglasCorp., Long Beach, Calif.

250. Davis,Richard E.: Probability ofLaminar 253. *Malik, M. R.; ** Wilkinson, S. P.;and Flow LossBecause of Ice CrystalEncounters. Pre- ***Orszag, S. A.: Instability and Transition on a sented at a Conferenceheld at Dryden Flight RotatingDisk. AIAA Journal,vol. 19, Sept. 1981 , ResearchCenter, Sept. 17- 18, 1981. Pages 75-94 pp. 1131- 1138. in Laminar Flow Control, NASA CP2218, March 1982. A81-44443# N82-20153# The stability ofthree-dimensional rotating A method for combiningthe cloud detector diskflow is investigated,including the effects observationresults from theGlobal Atmospheric of Coriolisforces and streamline curvature. The SamplingProgram (GASP) withKnollenberg probe numericalresults show that the critical Reynolds observations ofcloud particle concentration from number forestablishment of stationaryvortex flow otherprograms to derive estimates ofthe ambient is 287. These vorticesspiral outward at an angle concentration of particleslarger than a given ofabout 11 -2 deg,and transition to turbulence size was developed. The method was appliedto occurs when their totalamplification is about estimate the probability of encountering particle e". New experimentalresults are also reported concentrations which would degradethe performance on thespatial growth rates of thestationary oflaminar flow-control (LFC) aircraft. It is vortices. It is shown thatthe analysis gives concludedthat LF lossshould occur only about one growth rates that compare much better withthe percent of the time in clear air and that flight experimentalresults than do resultsobtained withinclouds should always result in a signifi- usingthe Orr-Sommerfeldequation. The experi- cant loss of LF, with 90 percent LF loss occurring mentalresults tend to supportthe numerical pre- aboutone percent of the time. Preliminary esti- diction that the number of stationaryvortices

55 variesdirectly with the Reynolds number. The N81-30389# calculations also indicatethe existence of weakly unstablepropagating (type 11) modes at low The method of multiple scales is used to Reynolds numbers (Critical Reynolds Number being describe a formally correct methodbased on the approximatelyequal to 49). nonparallellinear stability theory that examines the two andthree dimensional stability of com- 'Systems andApplied Science Corp., Hampton, Va. pressibleboundary layer flows. The method is **NASA, LangleyResearch Center, Hampton, Va. applied to the supersonic flat plate boundary ***Mass. Instituteof Technology, Cambridge, Mass. layer at Mach number 4.5. The theoreticalgrowth Contracts NAS1-15604 and NAS1-15894 rates are in good agreementwith the experimental resultsof Kendall. The method is also applied to theinfinite span swept wing transonicboundary 254.*El-Hady, Nabil M.; and*&glia, G. L.: layerwith suction to evaluatethe effect of the Application of Stability Theoryof "minar -Flow nonparallelflow on thedevelopment of crossflow Control.Final Report, 1 Sept. 1980-1 August disturbances. 1981. NASA CR-164709, Sept.1981, 68 pp. *Old Dominion Univ.,Norfolk, Va. N81-30387# Grant NSG- 1645

Four publicationsresulted from work per- formedduring the report period September 1, 1980 257. *El-Hady, Nabil M. : HADY- 1, A FORTRAN Pro- to August1,1981. Topics include: a computer gram forthe Compressible Stability Analysis of program forcalculating the linear incompressible Three-DimensionalBoundary Layers, Final Rept. or compressiblestability characteristics of the NASA CR-3467, Sept. 1981, 117 pp. laminarboundary layer on sweptwings; the growthof Goertler vorticesin compressible bound- N82- 12388# arylayers along curved surfaces; the effect of boundary layer growth on the stability ofcompres- A computerprogram HADY-1, forcalculating sibleflows; and theeffect of compressibility, thelinear incompressible or compressiblestabil- suction,and cooling on thecentrifugal instahil- itycharacteristics of the laminar boundary layer ity ofboundary layerflows along curved walls. on sweptand tapered wings is described. The For individual titles, see N81-30388 through eigenvalueproblem and its adjointarising from NE 1-30389. thelinearized disturbance equations with the appropriateboundary conditions are solved numer- *Old Dominion Univ.,Norfolk, Va. ically using a combinationof the Newton-Raphson Grant NsG- 1645 iterative schemeand a variablestep size inte- gratorbased on the Fhmge-Kutta-Fehlburg fifth- orderformulas. The integrator is usedin con- 255. *El-Hady, Nabil M.: HADY-1, A FORTRAN Pro- junctionwith a modified Gram-Schmidt orthonormal- gram forthe Compressible Stability Analysis of izationprocedure. The computerprogram HADY-1 "" ~ .. .. Three-DimensionalBoundary-.Layers. In"Applica- calculatesthe growth rates of crossflow or tionof Stability Theoryof Laminar Flow Control," streamwise Tollmien-Schlichtinginstabilities. It (N81-303871, Sept.1981, 22 pp. alsocalculates the group velocities of these disturbances. It is restrictedto parallel stability N81-30388# calculations, where theboundary layer (meanflow) is assumed to be parallel. The meanflow solution A computerprogram, HADY- 1, is describedfor is aninput to the program. calculatingthe linear incompressible or compressiblestability characteristics of thelaminar *OldDominion Univ.,Norfolk, Va. boundarylayer on sweptand tapered wings. The Grant NSG 1645 eigenvalueproblem and its adjointarising from thelinearized disturbance equations with the appropriateboundary conditions are solved numer- 258.*El-Hady, Nabil M.: On theEffect of Bound- icallyusing acombination of the Newton-Raphson aryLayer Growth on the Stability of Sompressible ~ iterative scheme anda variablestep size inte- Flows. NASA CR-3474, OCt. 1981, 45 pp. gratorbased on the Runge-Kutta-Fehlburg fifth- orderformulas. The integrator is usedin con- N81-33426# junctionwith a modified Gram-Schmidt orthonormal- izationprocedure. The method ofmultiple scales is used to describe a formallycorrect methodbased on the *Old Dominion Univ.,Norfolk, Va. nonparallellinear stability theory, that examines Grant NSG- 1645 the two- andthree-dimensional stability of compressibleboundary-layer flows. The method is applied to thesupersonic flat plate boundary 256.*El-Hady, Nabil M. : The Effectof Boundary layer at Mach number 4.5. The theoreticalgrowth Layer Growth on the Stability o~fompress~ible rates are in good agreementwith the experimental Flows.In: "Application of Stability Theory of resultsof Kendall. The method is also applied to Laminar Flow Control," (N81-30387#) Sept.1981, theinfinite span swept wing transonicboundary 10 PP.

56 layer with suction to evaluate the effect of the significant in that the airfoils exhibited the "" nonparallelflow on the developmentof cross-flow maximum theoreticalextents of laminar flow at disturbances. Reynolds numbers equivalent to currenthigh per- formancebusiness airplane operatingenvelopes. *Old Dominion Univ.,Norfolk, Va. None of the airfoilsurfaces received any special Grant NSG- 1645 preparation prior to flighttesting. No premature transition due to surfaceimperfections was found onany of the airfoils tested. In addition, no 259. *Riley, N. : No-n-Uniform SlotInjection into evidenceof crossflow instability was seen on any a LaminarBoundary Layer. Journal ofEngineering ofthe wings testedwith leading-edge sweep angles Mathematics,vol. 15, Oct. 1981, pp. 299-314. as high as 27O.

A82- 11375 The boundary-layertransition measurement methodsused included sublimating chemicals and Slot injection into a laminarboundary layer acousticdetection. A simplifiedtechnique for in both supersonicand subsonic flow is treated. usingsublimating chemicals without wing coverings It is notedthat the blowing rates are suffi- (forprotection against premature transition) was ciently large to provokean interaction between demonstrated using acenaphtene. the boundary layer and outerinviscid flow and that this interaction is accountedfor by triple- These recentboundary-layer experiment deck theory. The nonuniformityof the blowing resultsclearly show thatfor general aviation velocity models thechannel flow from which the flight Reynoldsnumbers, the necessaryairfoil injection takes place. surfacesmoothness conditions for NLF can be provided by use of compositeconstruction methods. *EastAnglia, University, Norwich, England Thus, the most significantremaining impediment to laminarflow applications is protection from ice and insectcontamination. 260. *Bower, Robert E.: Progressin Aeronautical Researchand Technology Applicable to Civil Air *NASA, LangleyResearch Center, Hampton, Va. Transports.International Meeting on hansporta- **George WashingtonUniv., Langley Research tionResearch: "State of the Art - Perspectives Center, Hampton, Va. andInternational Cooperation," held at Amalfi, Italy, Nov. 11-14, 1981, 51 pp. 262. *Smith, A. M. 0.: The BoundaryLayer A82- 13974# and I. AIAA Journal,vol. 19, Nov. 1981, pp. 1377- 1385. Recentprogress inthe aeronautical research andtechnology program being conducted by the -2- 10979# UnitedStates National Aeronautics and Space Administration is discussed.Emphasis is on COIR- The authorgives an account of hiscontribu- putationalcapability, new testing facilities, tions to boundary layertheory since 1945, includ- dragreduction, turbofan and turboprop propulsion, ingsuch developments as the DESA-2 laminar-flow noise,composite materials, active controls, airfoil,the amplification ratio method, finite- integratedavionics, cockpit displays, flight difference boundary layercalculation, and the management, andoperating problems. It is shown applicationof increasingly powerful computer thatthis technology is significantlyimpacting codes to thesolution ofboundary layer aerody- theefficiency of the new civil air transports. namicsproblems. Attention is alsogiven to the The excitementof emerging research promises even author'sextension oflaminar boundary analysis greaterbenefits to future aircaft developments. methods to turbulentflow structures. Other meth- odsconsidered include the Goertler problem,the *NASA, LangleyResearch Center, Hampton, Va. Falkner-Skan partialdifferential equation, the Galerkinand Picard methods, the Gram-Schmidt orthogonalizationprocedure, and Prandtl's mixing 261. *Holmes, Bruce J.; *Coy, Paul F.; *Yip, lengthrelation. Long P. ; *Brown, Philip W.; and **Obara, Clifford J.: NaturalLaminar Flow Data from Full *Sari Marino,Calif. ScaleFlight and Wind TunnelExperiments. Pre- sented at AIAA 8th Annual GeneralAviation Tech- nologyFest, Wichita, Kansas, Nov. 13-14, 1981, 263. *Dagenhart, J. Ray: AmplifiedCrossflow Dis- 21 PP. turbancesin the LaminarBoundary Layer on Swept ~ Wings withSuction. NASA TP1902, Nov. 1981, Results are presentedfor laminar flow exper- 88 PP. imentsand discussed in the context of related developmentswhich may lead to the realization of N82- 11391# practicalapplication of NLF for highperformance generalaviation airplanes. Recent full-scale Solutioncharts of the Orr-Sommerfeldequa- wind-tunneland flightexperiments have confirmed tion forstationary crossflow disturbances are theexistence of significant regions of NLF on presentedfor 10 typical velocityprofiles on a several powered aircraft.These findings are swept laminar-flow-control (LFC) wing. The crit-

57 ical crossflowmynolds number is shown to be a ence, the physical mechanism for decreasingtur- functionof a boundary-layershape factor. Ampli- bulencefor screens and honeycomb must be com- fication rates forcrossflow disturbances are pletelydifferent. Honeycomb with a downstream shown to be proportional to the maximum crossflow screen is anexcellent combination for reducing velocity. A computer stability program called turbulence. MARIA, employingthe amplification rate data for the 10 crossflowvelocity profiles, is con- *NASA, IangleyResearch Center, Hampton, Va. structed. This code is shown to adequately approximate more involvedcomputer stability codes using less than 2 percent as much computer time 266. *Nastrom, Gregory D.; **Holdeman, James D.; while retaining the essential physical disturbance and ***Davis, Richard E. : Cloud-Encounterand growthmodel. Particle-ConcentrationVariabilities from GASP -Data. NASA TP1886, Dec. 1981, 244 pp. *NASA, LangleyResearch Center, Hampton, Va. N82- 15677#

264. fcarmichael, E. H.: Low Reynolds Number Air- Summary statistics, tabulations, andvari- foil Survey, Vol. I, Final Rept. NASA CR-165803, ability studies are presentedfor cloud-encounter vol. I, Nov. 1981, 106 pp. andparticle-concentration data taken as part of theNational Aeronautics and space Administration N82- 14059# (NASA) GlobalAtmospheric Sampling Program (GASP). Cloudencounter was experiencedin about 15 per- The differencesin flow behavior on two centof the data samples; however, the percentage dimensionalairfoils in the critical chordlength varieswith season, latitude, and altitude (par- Reynolds number comparedwith lower andhigher ticularlydistance from the tropopause). In Reynolds number are discussed. The largelaminar agreementwith classical storm models, thedata separationbubble is discussedin viewof its show more cloudsin the upper troposphere in importantinfluence on critical Reynolds number anticyclonesthan in cyclones. The concentration airfoilbehavior. The shortcomingsof application ofparticles with a diametergreater than 3 (un of theoreticalboundary layer computations which also varies with time andlocation, depending are successful at higherReynolds numbers to the primarily on thehorizontal extent of cloudiness. critical regime are discussed. The largevaria- Some examplesof the application of the statisti- tionin experimental aerodynamic characteristic cal data to theestimation of the frequency of measurementdue to small changes in ambienttur- cloudencounter and laminar-flow loss to be bulence,vibration, and sound level is illus- expected on long-rangeairline routes are also trated. The difficultiesin obtaining accurate presented. detailed measurements in free flight anddramatic performanceimprovements at critical Reynolds *Control Data Corp., Minneapolis,Minnesota number, achievedwith various types of boundary **NASA, LewisResearch Center, Cleveland, Ohio layertripping devices are discussed. ***NASA, LangleyResearch Center, Hampton, Va. (Note: This is a comprehensivedevelopment of: *Low Energy TransportSystems, Capistrano Beach, (1) AIM-81-0308, Jan. 12-15,1981 and (2) Journal Calif. ofAircraft version submitted July, 1981.) NASA G4059B

267. *Reed, Helen L.: The lbllmein-Schlichting 265.*Scheiman, James: ComparisonofExperimen- Instability of LaminarViscous Flows. Ph.D. tal andTheoretical Turbulence Reduction .earac-- Thesis, VirginiaPolytechnic Institute and State teristics forScreens, Honeycomb, and Honeycomb- Univ., Dec. 1981, 210 pp. (Available from ScreenCombinations. NASA TP1958, Dec. 1981, UniversityMicrofilms.) 58 PP- The lbllmien-Schlichtinginstability is N82- 14055# analyzedfor a varietyof laminar viscous flows. Theseinclude two-dimensional incompressible, A half-scale model of a portionof the axisymmetricincompressible, and three-dimensional Langley8-Foot Transonic Pressure Tunnel was used compressibleflows with suction. For the incom- to conduct some turbulencereduction research pressibleflows, a linearoptimization scheme is usingscreens, honeycomb, andcombinations developed todetermine placement of and flow rate thereof. The experimentalresults are compared throughsuction strips. The importantconclusion withvarious theories. Screens alone reduce axial is thatsuction should be concentratednear the turbulence more thanlateral turbulence; whereas, Branch I neutralstability point. The scheme is honeycomb alonereduces lateral turbulence more found to accuratelypredict the experimental thanaxial turbulence. Because of this differ- resultsin the two-dimensional case. For the

58 /1 compressibleflows, a method forfollowing one metric model at speedscorresponding to __'' specific wave toascertain the characteristics of Re(L) = 5,000,000 - 6,000,000. The developmentof the most unstabledisturbance is presented. theturbulent boundary layer was compared for that of sinteredmetal, honded screening,and perfo- *Virginia Polytechnic Institute and State Univ. , ratedsheet and then to that for the flow over a Blacksburg, Va. solid smooth wall and a solid, sand-roughened NASA Grant NSG-1255 and ONR N00014-75-C-0381 wall. The comparisonsreveal that the effect of Consultantsto Westinghouse Electric andNaval porosity is toshift the logarithmic region of the Underwater Sea Center. wall law down by a certain amount from the solid wallresults and toincrease the skin friction values by about 30 - 40%. The downward shift of 268. Althaus, Dieter; and Wortmann, F. X.: thelogarithmic region of the wall lawand the StuttgarterProfilkatalog I: messergebnisseaus increase of theskin friction value by the cow dem Laminarwindkanaldes Instituts fur Aerodynamik binedeffects of small roughnessand porosity are undGasdynamik derUniversitat Stuttgart - 1981. foundto be roughly the sum of theirindividual (Experimentalresults from the laminar wind effects. tunnel. ) New edition. Vieweg, Braunschweig, 1981, 320 pp. (Book). 'VirginiaPolytechnic Institute and State Univ., Blacksburg, Va. QA929.A42 (1981) V81-22050 (1981) NASA-supported research.

Copiesof this catalog must be ordered directly from the UniversitH'tStuttgart. (NASA- 271. *Reynolds, G. A. : Experiments on theStabil- LaRC libraryhas an mglish edition of this ity of theFlat-Plate with Suction. Ph.D. Thesis, publication.) VirginiaPolytechnic Institute and State Univ., Jan.1982, 157 pp. (Availablefrom University Microfilms.) 269. *Aircraft Energy Efficiency.Overview: NASA-Facts 96/9-80; NASA 1M-80454, 1981, 7 pp. Theseexperiments consider the effects of suctionin stabilizing the laminar boundary layer N81-28083# withrespect to Tollmien-Schlichting wave growth. Two-dimensional waves areintroduced into the Sixadvanced technology development projects boundarylayer using a vibratingribbon andsuc- thatcould cut fuel consumption of future civil tion is appliedat the surface of the model via air transports by as much as 50 percentare high- two Dynaporeporous panels. Suction is applied lighted. Theseinclude improved engine compo- either in a spatiallycontinuous fashion or nents;better engine design; thin short blades for throughdiscrete spanwise strips. Detailed mean turbopropaircraft; using composite primary struc- flowand disturbance amplitude measurements indi- turesfor weight reduction; the use of supercriti- catethat discrete suction can be as effective as cal wings,higher aspect ratio, and winglets for continuoussuction and that suction is more effec- improvedaerodynamics; activecontrols; and lami- tive when placedforward on the model andnot in narflow control. The timespan of each of the theregion of maximum disturbancegrowth rate. six efforts and NASA's expectedexpenditures are alsodiscussed. *VirginiaPolytechnic Institute and StateUniv., Blacksburg, Va. *NASA, Washington, D.C. Grant NSG- 1608

270. *Kong, F. Y. ; andfSchetz, J. A. : !Turbulent 272. *Biringen,Sedat: Laminar Flow hansition: Boundary LayeroverPorous Surfaces with Different A Large-Eddy Simulation Approach. NASA CR-3518, SurfaceGeometries. AIAA 20thAerospace Sciences Feb. 1982, NEAR-TR-251,33 pp. Meeting,Orlando, Florida, Jan. 11-14, 1982, 11PP. N82- 19499#

A IAA -82-0030 A82- AIAA-82-0030 17742# A vectorized,semi-implicit code is developed forthe solution of thetime-dependent, three- The turbulentboundary layer over three dimensionalequations ofmotion in plane porous walls withdifferent surface geometries Poiseuilleflow by the large-eddysimulation tech- was studiedin order to investigate the individ- nique. The code is tested by comparing results ualinfluences of porosityand small roughness, withthose obtained from the solutions of the Orr- as well as their combined effects, on turbulent Sommerfeld equation.Comparisons indicate that boundary layerbehavior. The tests were finite-differences employed along the cross-stream conducted in a 2m x 2m tunnel on a large axisym- directionact as an implicitfilter. This removes

59 the necessity of explicit filtering along this 275. 'Dagenhart, J. R. ; and*Stack, J. P. : Bound- direction(where a nonhomogeneous mesh is used) aryLayer Transition Detection Using Flush-Mounted forthe simulation oflaminar flow transition into Hot-Film Gages and Semiconducter Dynamic- -Pressui turbulencein which small scaleturbulence will be Transducers.Presented at the AIAA 12thAerodyT accountedfor by a subgrid scale turbulence model. namic %stingConference, Williamsburg, va., March 21-24, 1982. *NeilsenEngineering Si Research,Inc., Mountain View, Calif. AIAA-82-0593 Contract NAS1- 16289 Flush-mountedhot-film gages and semiconducter dynamic pressuretransducers (microphones) 273. *Harvey, W. D.; and'Pride, J. D., Jr.: -The are compared as boundarylayer transition detec- NASA LangleyLaminar Flow ControlAirfoil Experi- tiondevices. The filmsand microphones are -ment. Presentedat the AIAA 12thAerodynamic flush-mounted on theside wall ofa small, low- TestingConference, Williamsburg, Va., March 21- speed,open-circuit wind tunnel. The variation of 24, 1982, 25 pp. the dynamicand root-mean-square voltage signals forthe two detectortypes are comparedover the AIAA-82-0567 rangefrom laminar through transitional to fully turbulentflow. The hot-filmsignals changedis- A largechord swept supercritical laminar tinctlyas the Reynolds number is increased.In flowcontrol airfoil has beendesigned, con- contrast,the microphone signals change little in structed, andsoon will be tested as a part of characterover the Reynolds number range.These NASA-Langley's ongoingresearch program to siq observationsindicate that the hot-film gage is nificantlyreduce drag and increase aircraft thesuperior transition detection device. efficiency.This experiment is aimed atvalidat- ing prediction techniques and establishing a tech- *NASA, LangleyResearch Center, Hampton, Va. nologybase for future transport designs. Unique featuresinclude a highdesign Mach number and shock-freeflow, as well asthe minimization of 276.*Floryan, J. M.; and*Saric, W. S.: Stabil- thelaminarization suction through choice of air- ity of GGrtler Vorticesin BoundaryLayers. AIAA foil geometryand pressure distribution. Success 12thFluid andPlasma Dynamics Conference, of theexperiment requires transonic tunnel flow Williamsburg, Va., July 23-25, 1979, 18 pp. AIAA of excellentquality which simulatesthat in free Journal,vol. 20, March 1982,pp. 316-324. airabout an infinite yawed model. Modifications made to the NASA Langley/B-Ft.Transonic Pressure 1497R AIAA- 79- A82-23830# Tunnel to meet theserequirements are discussed. A formalanalysis of &rtler-type instability *NASA, LangleyResearch Center, Hampton, Va. is presented. The boundary-layerand disturbance equations are formulated in a general,orthogonal, curvilinearsystem of coordinates constructed from 274. *Newman, Perry A.; *Anderson, E. Clay;and theinviscid flow over a curved surface. Effects *Peterson,John B., Jr.: NumericalDesign of the ofcurvature on theboundary-layer flow are Contoured Wind-Tunnel Linerfor the NASA Swept- analyzed. The basicapproximation for the distur- Wing LFC Test. Presented at the AIAA 12th Aero- banceequations is presented and solved numeri- dynamic TestingConference, Williamsburg, Va., cally.Previous analyses are discussedand March21-24, 1982, 12 pp. compared withour analysis. It is shown thatthe generalsystem of coordinatesdeveloped in this AIAA-82-0568 A82-24656# analysisand the correct order-of-magnitude analysis of thedisturbance velocities with two veloc- A contoured,nonporous, wind-tunnel liner has ityscales leads to arational foundation for beendesigned in order to simulate a free-flight, future work inGortler vortices. infinite yawed-wing, transonic-flowcondition abouta large-chord supercritical-section, *VirginiaPolytechnic and State Univ.,Blacksburg, laminar-flow-control (LFC) , swept-wing test panel. Va . The numericalprocedure developed for this aero- Grant NsG- 1255 dynamic linerdesign is based upon thesimple idea ofstream-lining and incorporatesseveral existing transonic andboundary-layer analysis codes. A 277. *Nastrom, G. D.; **Holdeman, J. D.; and summary of theentire procedure is presented to ***Davis, R. E.: CloudEncounter and Particle indicate: Whatwas doneand why, thesequence of Number DensityVariahilities from GASP Data. steps, and theoverall data flow. The liner is Journal of Aircraft,vol. 19, April,1982, being installed in the NASA Langley8-Foot Tran- pp. 272-277. sonic Pressure Tunnel(TPT). Test resultsindi- catingthe aerodynamic performance of the liner AIAA-8 1-0308R are notyet available; thus, the liner design resultsgiven here are examples of thecalculated Summary statistics and variabilitystudies requirementsand the hardware implementation. arepresented for cloud-encounter and particle number densitydata taken as part of the NASA *NASA, LangleyResearch Center, Hampton, Va. GlobalAtmospheric Sampling Program (GASP) aboard

60 B

commercialBoeing 747 airliners. On average,280. *Holmes, Bruce J.; and**Obara, Clifford, .gF cloudencounter is shown about 15% ofthe i:;-~- Natural onof Implications and J.: Observations..~"..~~~~~~~ 52,164 data samplesavailable, but this valueLaminar Flow on Practical AirplaneSurfaces. 13th .. . ~ ~-~ ~ varieswith season, latitude, synoptic weather Congress of the ICAS/AIAA Aircraft Systemsand situation, and distance from thetropopause. The TechnologyMeeting, Aug. 22-27, 1982, Seattle, number densityof particles (diameter greater than wash. 3pn1 also varieswith time andlocation, and depends on thehorizontal extent cloudiness.of ICAS-82-511

*Control Data Corp., Minneapolis, Minn. Recent flightexperiment observations have **NASA, Lewis ResearchCenter, Cleveland, Ohio recordedextensive regions of natural laminar flow ***NASA, LangleyResearch Center, Hampton, Va. (NLF) boundarylayers in the favorable pressure (Note: See #217 inthis bibliography for the gradientregions on several smooth,production- AIAA paper, AIAA AerospaceSciences Meeting, qualityairframes. These observationshave St.Louis, Mo., Jan. 12-15, 1981.) resulted in a new appreciationof the operational feasibility for obtaining NLF on certain modern practicalairplane surfaces. The flightexperi- 278. *Campbell,Richard L.: Effectof Nacelles on ments were conducted on eightdifferent airplanes, Aerodynamic Characteristics ofan Executive-Jet includingpropeller- and turbojet-powered configu- ~. ." ~~~~~~

" . Model with Simulated,~. Partial-Chord, Laminar-Flow- rations andairframes constructed of aluminum or Control Wing Glove. NASA 'IM-83271, April 1982, composites. The experiments were conducted on 103 pp. surfaces which received(with two notedexcep- tions) no specialpreparation of contours or N82-22217# surfacewaviness for NLF considerations.Experi- mentallyobserved laminar flow transition Reynolds Tests were conducted inthe Langley High- numbersranged between 1 and 5 million on the Speed 7- by 10-FootTunnel using a l/l0-scale propeller-drivenairplanes andexceeded 11 million model ofan executive jet to examine theeffects on thebusiness jet tested. ofthe nacelles on the wing pressures and model longitudinalaerodynamic characteristics. For the The summarized results of theseexperiments presentinvestigation, each wingpanel wasmodi- includecomparisons between measured and empiri- fiedwith a simulated,partial-chord, laminar- callypredicted allowable surface waviness, com- flow-controlglove. Horizontal-tail effects were parison of flight-measuredwing profile drag with also briefly examined. The tests covered a range tunneldata, comparisons of fixed and freetransi- of Mach numbers from 0.40 to 0.82 and lift coeffi- tion airfoil and airplaneaerodynamics, and com- cients from 0.20 to 0.55.Oil-flow photographs of parisons betweenobserved sweep effects on laminar the wing atselected conditions are included. flowand an empirical spanwise contamination criterion. Also discussedare the observations of *NASA, LangleyResearch Center, Hampton, Va. laminarflow in the propeller slipstreams of two airplanes, andan example of insect debris contamination on an NLF wing. Severalimplications of

279. Harvey, W. D.: -~NASA ~~ Supercritical 'Laminar theseobservations are alsodiscussed, including Flow ControlAirfoil Experiment. Energy thenecessity for both fixed and freetransition Conservationin Air TransDorts Meetincr.-. Toronto, flighttesting on airplaneswith surfaces smooth Canada, May 4-6, 1982, 47 pp, 34 figures, 1 table, enough forlaminar flow. and 45 references. *NASA, LangleyResearch Center, Hampton, Va. **Kentron International, Hampton, Va. A largechord swept supercritical laminar flowcontrol airfoil has beendesigned, constructed, and soon will betested as a part of 281. *Petersen,Richard H.; and*Maddalon, NASA-Langley's ongoingresearch program to sig- Dal V.: NASA Research on ViscousDrag Reduc- nificantlyreduce drag and increase aircraft tion.13tX~Congress of the International Council efficiency. This experiment is aimed at validat- ofthe Aeronautical Sciences (ICAS)/AIAA Aircraft ing prediction techniques and establishing a tech- Systemsand Technology Meeting, Seattle, Wash., nologybase for future transport designs. Unique Aug. 22-27, 1982, 11 pp. featuresincluded a highdesign Mach number and shock-freeflow as well as theminimization of the ICAS- 8 2- 5 14 Also see NASA 1M-84518 laminarizationsuction through choice of airfoil geometryand pressure distribution. Success Current NASA researchpoints toward exciting ofthe experiment requires transonic tunnel flow opportunitiesfor large reductions in viscous of excellentquality whichsimulates that in free drag.Research is underway on naturallaminar air aboutan infinite yawed model. Modifications flow,laminar flow control by suction,and turbu- made to the NASA Langley/8-Ft.Transonic Pressure lentdrag reduction. Preliminary results suggest Tunnel to meet theserequirements are discussed. that a significant amount ofnatural laminar flow can be achievedon small, straight-wingairplanes. *NASA, LangleyResearch Center, Hampton, Va. On larger, swept-wing aircraft,laminar flow con-

61 trol by distributed suction is expected to result The hybridlaminar flow control (HLFC) con- insignificant fuel savings. The area overwhich cept was examined in whichleading-edge suction is laminarflow control is applieddepends on trade- used in conjunction with wing pressure distribu- offsinvolving structural complexity, maintenance, tion tailoring to postponeboundary layer transi- and cost. Several methods of reducingturbulent tion andreduce friction drag. A parametricstudy skin friction by altering the turbulence structure was conducted to determineairfoil design charac- itself have shown promise in exploratory testing. teristics required€or laminar flow control (LFC). This paper reviews thestatus of these technolo- The aerodynamicdesign of an HLFC wing for a gies and indicates the benefits of applying them 178-passenger commercial turbofantransport was to future aircraft. developed,and a drag estimate was made. Systems changesrequired to install HLFC were defined,and *NASA, LangleyResearch Center, Hampton, Va. weightsand fuel economy were estimated. The potentialfor 9% fuelreduction for a 3926-km (2120-nmi) mission was identified. 282. *Braslow, Albert L.: Laminar Flow. McGraw- Kill Encyclopedia Yearbook ofScience and Tech- *Boeing Commercial Airplane Co., Seattle, Wash. nology, 1982-1983, pp. 272-275, Sept. 1982. Contract NAS1-15325

The increasein cost of petroleum fuels in the past severalyears, greater than the general 285.*Ecklund, R. C.; and Williams, N. R.: inflationof prices, hasraised the percentage of Laminar Flow Control SPF/DB Feasibility aircraftoperating expense due to fuel to the Demonstration,Final Report. NASA CR-165818, point where fuelefficiency is the keydesign goal 1982, 50 pp. forfuture derivative and new aircraft. NASA and theaircraft industry have identified technologies N82-21532# thatcan significantly reduce aircraft fuel consumption in coming yearsand are activelypursuing The feasibilityof applying superplastic researchand technology development programs. One forming/diffusionbonding (SPF/DB) technology to of these technologies is theattainment of exten- laminarflow control (LFC) systemconcepts was siveregions of laminar air flow over aircraft demonstrated.Procedures were developed to surfaces.Although this offers the greatest producesmooth, flattitanium panels, using thin potentialfor fuel conservation of any single new 0.016 inchsheets, meeting LFC surfacesmoothness technology, it involvesthe greatest challengesin requirements. Two largepanels 28 x 28 inches the areas of aircraftmanufacture, maintenance, were fabricated as finaldemonstration articles. andoperational procedures required to provide The first was flat on thetop andbottom sides acceptablereliability at reasonable cost. This demonstrating the capability of the tooling and article discussesthe phenomenon oftransition theforming and diffusion bonding procedures to fromlaminar to turbulent flow andwhat has been produceflat, defect free surfaces. The second learnedabout its prevention. panel was configuratedfor LFC porouspanel treatment by formingchannels with dimpled projections *NASA, LangleyResearch Center, Hampton, Va. on the top side. The projections were machined (retired) away leavingholes extending into the panel. A perforatedtitanium sheet was adhesivelybonded overthis surface to complete the LFC demonstra- 283.Krishnaswamy, R.; andNath, G.: A Parametric tionpanel. The finalsurface was consideredflat DifferentialVersion with Finite-Difference Scheme enough to meet LFC requirementsfor a jet trans- Applicable to a Class of Problems -in Boundary port aircraftin cruising flight. Layer Flow withMassive Blowing. Computers and Fluids,vol. 10,no. 1,1982, pp. 1-6. *Douglas Aircraft Co., Long Beach, Calif.

A numericalprocedure, based on the parametric differentiation and implicit finite differ- 286.*McQuilkin, Fred T.: Feasibilityof SPF/DB ence scheme, hasbeen developed for a class of TitaniumSandwich for LFC Wings. NASA CR-165929, problems inthe boundary-layer theory for saddle- 1982. pointregions. Here, theresults are presented forthe case of a three-dimensionalstagnation- The feasibilityof fabricating SFP/DB tita- pointflow with massive blowing. The method com- nium structuresof sufficient smoothness to be pares very well withother methods for particular usedfor laminar flow wing surfaces has been cases (zero or small mass blowing).Results demonstrated. lku methodsof fabricating panels emphasizethat the present numerical procedure is which meet thesurface smoothness criteria have well suitedfor the solution of saddle-point flows beendemonstrated. The firstconsists ofsuper- with massiveblowing, which could not be solvedby plastically forming/diffusion bonding a panel other methods. using steel dies,and then machining the surface to therequired flatness and finish after forming.This approach, however, has been estimated 284. *PreliminaryDesign Dept., Boeing Commercial to be more costlythan the second approach, in Airplane Co. (BCAC) : HybridLaminar Flow Control which thepanel is formed againstceramic platens -Study,Final Technical Rept.Boeing Rept. no. whichproduce the desiredsurface smoothness D6-49359; also NASA CR-165930, 1982, 201 pp. withoutsubsequent finishing. Acceptable surface

62 .. . i

quality as well asfeasibility of the laminarflow to larger wingpanels, fabrication of separate LFC control (LFC) surfacedesign, in which separate strips, and theapplication of thetechnology to stripsincorporating theboundary layer bleed military aircraft. provisions are bonded into slots on thesurface, hasalso beendemonstrated. Recommendations for *RockwellInternational, North American Aircraft future work arepresented, including continued Operations, Los Angeles,Calif. study on additionalsmoothness concerns, scale-up Contract NAS1-16236

The followingcitations are includedfor the sake of completeness. Abstracts for some were not available and some were identified too late to be includedin chronological order.

287. *SariC, W. S.; and*Reynolds, G. A.: Experi- A82-26131

__ments""_" on the".~~~~Stability and Transition of Two- Dimensi-onal andThree-Dimensional Boundary Layers Effects of screensand perforated plates With Suctiiiiiri. "FinalRept., NASA CR-157256, (grids) on free-streamturbulence are studiedin July 1979, 71 pp. several test flowconditions. The level,structure anddecay of the turbulence generated by such N79-27464X "manipulators"depend in part on theirshear-layer instabilities, andcan therefore be modified by The preliminaryexperimental developent work insertingadditional devices immediately down- directedtowards the understanding of transition stream. The performance of screensand some per- in boundary layerswith suction is presented. %e foratedplates is found to depend on thecharac- basicstability experiment was established and the teristics of the incomingflow such as velocity, facility was certified. turbulencelevel and spectra.Combinations of perforatedplates and screensare found to be very *VirginiaPolytechnic Institute and State Univ., effective flowmanipulators. By optimizingthe Blacksburg, Va. intermanipulatorseparation and carefully matching Grant NSG 1358 thescales between themanipulator pair, the tur- bulencedecay rate downstreamof a grid can be quadrupled. 288. *Babbitt, P. J. : Modern Fluid Dynamics of Subsonicand Transonic Flight. AIAA International *IllinoisInstitute ofTechnology, Chicago, 111. Meetingand Technical Display on GlobalTechnology **ColoradoState Univ., Fort Collins, Colo. 2000, Baltimore, Md.,May 6-8, 1980, 39 pp., 65 refs. 290.*Chen, J. L. S.; and*Jeng, M. C.: Fluid AIAA-80-0861 -0-33274# Injection to a LaminarBoundary Layer with Variable Wall Mass andHeat Flux. AIAA/ASME 3rd The paperdiscusses a number of factors, Joint Thermophysics,Fluids, Plasma and Heat termedresearch drivers, which areexpected to TransferConference, St. Louis, Mo., June 7-11, provide much of thestimulus for research in the 1982. subsonic and transonicflight regimes in the com- ingdecade. The researchdrivers discussed com- ASME-82-HT61 prisethe need forenergy efficiency, new and improved facilities,better instrumentation, more *University of Pittsburgh,Pittsburgh, Pa. capableand efficient computers, theoretical methodologyrefinements, increased use of optimi- zationtechniques, and military requirements. 291. *Nayfeh. A. H.; and*Reed, H. L.: Stability

Illustrations ofadvances inaircraft aerodynamics of Flow over Axisymmetric"_ . . Bodies with Porous Suc- at subsonicand transonic speeds are presented, tionStrips. AIAA/ASME 3rdJoint Tbermophysics alongwith a discussion of futureresearch oppor- Fluids, Plasmaand Heat TransferConference, tunities andtrends. Particular attention St.Louis, Mo., June 7-11,1982. is givento airfoil and basicfluids research designedto reduce skin-friction drag. (Laminar AIAA-82-1025 flow is discussedbeginning on page 15. ) *VirginiaPolytechnic Institute and State Univ., *NASA, LangleyResearch Center, Hampton, Va. Blacksburg, Va.

289. *Tan-Atichat, J.; *Nagib, H. M.; and 292. *Reynolds, G. A.: and**Saric, W. S.: Exper- **Loehrke, R. I.: Interaction ofFree-Stream iments on the Stability of theFlat-Plate Boundary ..~~~ Turbulencewith Screens and Grids - A Balance Layerwith Suction. AIAA/ASME 3rdJoint Thermo- BetweenTurbulence Scales. Journal of Fluid physics,Fluids, Plasmaand Heat TransferConfer- Mechanics,vol. 114, Jan.1982, pp. 501-528. ence,St. Louis, Mo., June 7-1 1, 1982.

63 AIM-82- 1026 297.*Bennett, J. A.: External AerodynamicDesign for a Laminar Flow Control Glove on a Lockheed Jet *NationalBureau of Standards, Washington, D.C. Star Wing. 13thCongress of the International **Virginia Polytechnic Institute and State Univ. , Council of the AeronauticalSciences (ICAS)/AIAA Blacksburg, Va. Aircraft Systemsand Technology Meeting, Seattle, Wash., Aug. 22-27, 1982.

293.*El-Hady, N. M.; and *Vem, A. K.: Insta- ICAS-82-513 bility ofCompressible Boundary Layers Along Curved Walls withSuction or Cooling. AIAA/ASME *Lockheed-Georgia Co., Marietta, Georgia 3rdJoint Thermophysics, Fluids, Plasma and Heat TransferConference, St. Louis, Mo., June 7-11, 1982. 298. *Thelander, J. A.; *Allen, J. B.; and * Welge, H. R.: AerodynamicDevelopment of Laminar Flow AIAA-82- 10 10 Controlon Swept Wings UsingDistributed Suction ~~.. ". . "" __ ThroughPorous Surfaces. 13th Congress of the *Old Dominion Univ.,Norfolk, Va. InternationalCouncil of the Aeronautical Sciences (ICAS)/AIAA Aircraft Systemsand Technology Meet- ing,Seattle, Wash., Aug. 22-27, 1982. 294. *Hankey, W. L.;and *Shang, J. S.: Natural Transition - A SelfExcited Oscillation. AIM/ ICAS- 82- 5 12 ASME 3rdJoint Thermophysics, Fluids, Plasma and Heat TransferConference, St. Louis, Mo., Developmentof a laminarflow control system June 7-11,1982. utilizingdistributed suction through porous stripsis reviewed.Recent improvements in elec- AIAA-82- 10 1 1 tron beam perforationtechnology have greatly enhancedthe potential for practical LFC applica- *Air ForceWright Aeronautical Labs., Wright- tion. Designof airfoilshapes compatible with Patterson AFB, Ohio LFC on swept wings is outlined. Boundary layer stabilityanalysis results anddetermination of suctiondistributions are reviewed.Considera- 295. *Morris, P. J.; and *Byon, W.: The Stability tionsfor an operational system for protection of the AxisymmetricBoundary Layer on Circular a .~ from ice and insectcontamination are noted. Cylinder. AIAA/ASME 3rdJoint Thermophysics, Results of a swept wing model test and plansfor Fluids, Plasmaand Heat !TransferConference, a LFC leadingedge glove flight test program are St.Louis, Mo., June 7-11, 1982. reviewed.

AIAA-82-1012 *Douglas Aircraft Co., Long Beach, Calif.

*Penn. State Univ., UniversityPark, Pa. 299. *Pearce, W. E.: Progress at Douglas onLami- nar Flow ControlApplied to Commercial Transport 296. *Reed, H. L.;and *Nayfeh, A. H.: Stability Aircraft.13th Congress of theInternational ofCompressible Three-Dimensional Boundary-Layer Councilof the Aeronautical Sciences (ICAS)/AIAA Flows. AIAA/ASME 3rdJoint Thermophysics, Fluids, Aircraft Systemsand Technology Meeting, Seattle, Plasmaand Heat TransferConference, St. Louis, Wash., Aug. 22-27, 1982. Mo., June 7-11, 1982. ICAS-82- 153 AIAA-82- 1009 *Douglas Aircraft Co., Long Beach, Calif. *VirginiaPolytechnic Institute and State Univ., Blacksburg, Va.

64 APPENDIX

The 49 entries in this appendix have publication dates prior to 1976 but they were notincluded in NASA RP-1035 (citation 141). Many of them were notfreely available when thatreport was published. They are includedhere because of their relevance.

Thesedocuments have been included inthe author index as A-1, A-2, etc., and are also arranged in chronological order.

65 APPENDIX

A-1. *Johnson, D.: BriefMeasurements of Insect The lateral components consist almost entirely of Contaminationon Aircraft Wings. Tech. Note Aero. a similar low-frequency contribution. With all 2164, May 1952, 11 pp. (Available to U.S. Gov't. thescreens in the tunnel the low levelof turbu- Agencies Ck7ly.l lence is confined to a restricted area near the centreof the tunnel with flashes of high- N-53305 from STIF intensityturbulence spreading a considerable distance from the walls. Noise measurementswith *Royal AircraftEstablishment, Farnborough, thehot-wire microphone inthe middle of the work- England. ing-section showed that above a tunnelspeed of 150 ft/sec thelongitudinal component consisted A-2. *Coleman, W. S.: Wind TunnelExperiments on mainlyof noise. Some measurements were also made thePrevention of Insect Contamination by. Means-~f withthe hot-wire microphone in the turbulent Soluble Films and by Liquids Discharged~ -Over- _the boundarylayer on the walls. Surface. ALCC Note 39 (Note W.T. 131),British Minist.Supply, July 1952. (Available to U.S. *AeronauticalResearch Council, London, England Gov't.Agencies and Their ContractorsOnly.)

CN-142,061 A-5. *Goldsmith, J. : Experiments With Laminar X80-71190# Flow Near theJuncture of a Fuselageand a Wing *Ministryof Supply, London, England Trailing Edge. NorthropCorp., Norair Div., Rept. NO. NOR-59-306,BLC-120, June1959, 114 pp.

A-3. *Rogers,Kenneth H. : Investigationof the N79-77133 PressureDistribution in Suction Ducts. Rept. No. BLC-22, NorthropAircraft, Inc., Nov. 1953, The problemof maintaining laminar flow in 45PP- theregion of the juncture of two airplane components is beingconsidered at Norair, and the AD 25 566 N79-75676 possibilityfor laminar flow in the region of a wingleading edge and fuselage juncture has been Results of tests to determinethe pressure demonstrated. These junctureexperiments were distributionin suction ducts for aircraft with extended to includethe wing trailing edgeand boundarylayer control are presented.This report fuselageintersection, and it is withthe latter includesthe material presentedin Northrop Air- subject that this report deals. craft,Inc. Report No. BLC-13, "PreliminaryInves- tigationof the Pressure Drop inSuction IXIcts," The experimentsdemonstrated that it is pos- plusthe results of additional tests made subse- sible to achievelaminar flow in and downstream of quentto the release ofthe preliminary report. thejuncture of a wingand flat plate. The exper- Results show thatthe pressure drop along the duct iments also demonstratethat laminar flow is is smallif turning-vanes are provided to turnthe facilitated by installing two small vortexgenera- inletflow into the direction of theduct. This tors onthe wing trailing edgenear the intersec- is due to thereduced losses inthe duct and to tionof the wingand plate. The vorticesgener- themixing of the duct flow withthe flow from the ated in this manner seem to "sweep" the wing wake turning-vanes(diffuser effect). Without turning- away from the plate; consequentlylarger wake vanes,the pressure drop along the duct is disturbancesthan formerly believed can be toler- increasedconsiderably. Within reasonable limits, atedwithout causing transition on thefuselage variationsin duct taper, variations in the ratio (or plate) downstreamof a wing. ofinlet velocity to duct velocity, and variations in Reynolds number of theduct flow have only 'NorthropCorp., Norair Div.,Hawthorne, Calif. minor effects upon thepressure distribution along theduct. A-6. *Carmichael, B. H.; and*Pfenninger, W.: *NorthropAircraft, Inc., Hawthorne, Calif. SurfaceImperfection Experiments on a Swept Lami- narSuction Wing. Northrop Corp., Norair Rept. No. NOR-59-454,BLC-124, August1959, 34 pp. A-4. 'Schuh, H.; and'Winter, K. G.: The R.A.E. 4-ft x 3-ftExperimental bw-Turbulence Wind N79- 77 135 ~ ~~___ Tunnel.Part 11. MeasurementsofTurbulence ~" Intensity andNoise in the Working-Section. The 30° swept laminarsuction wing was R. Fi M. 2905, British, A.R.C., 1957,- 20 pp. modified by extendingsuction forward to 0.5 percentchord. This configuration was testedwith N78- 7859 1 andwithout surface waviness at both the 5- by 7-Foot Universityof Michigan and the 7- by With all thescreens fitted in the tunnel, 10-Foot Norair Low Turbulence Wind Tunnels. The theintensities of lateral components are ofthe total dragcoefficients for the clean model were same order as thelongitudinal componentand range practicallyidentical over theReynolds number fromabout 0.01% to 0.03% ofthe mean speed. rangetested. Frequencyanalyses have shown thelongitudinal components to consistof fan frequencies and a Allowablevalues of surface waviness low-frequencycontribution at about 5 to 10 C.P.S. (1/400 < h/h < 1/70)appear to be very similar to

66 APPENDIX

thosepreviously found on unswept low dragsuction ::--47 N79-77132 wings inthe nonsuction region. Allowable wave height was found to be proportional to (wave The first series ofexperiments on this wing length) 'I2(Reynolds and ?he single provedthat full chord laminar flow can be main- wave results were well described by tained on aswept wing with adequate suction throughoutthe strong cross flow region in the aft h2 - 3/2 59,000. The allowable wave height portion of the w'ng at chordReynolds numbers of . c(Rc' ii atleast 12 x 10 . Inaddition, the leading edge offour waves in series was less #anhalf #at cross flow instability was notcritical at 00 and fora single wave. Criticalwaviness appeared +lo, but was critical at a chordReynolds number identical at 27 and 75 percentchord locations for above7 X lo6for -lo angle of attack. eithersingle or multiple waves. Possibleoutflow of air from the slots due to excessively low In thepresent series of tests,the swept static pressures over a wave may often limit the winglaminar suction model has been modified by permissiblesurface waviness. Total drag coeffi- theinstallation of slots forward to achievelami- cients andsuction distributions with waves narflow at higher Reynolds numberswhere the less installed and just subcritical conditions were severeleading edge cross flow becomes critical at identicalwith clean model data. Oo angle of attack.Full chord laminar flow and low frictiondrags wereobserved up tothe tunnel- The effect of slot spacing on thesuction limited wing chordReynolds number. The measured requirementsof the clean model was investigated dragsat Oo areslightly lowerthan those from the by pluggingtwo-thirds of the slots. This first series of tests andthere were no indica- increasedthe spacing in the rear half of the tionsthat the forward slots caused any distur- modelfrom 0.55 percentchord to 2.2 percent banceswith or withoutsuction applied. The chord. No increasein suction quantity for full satisfactory pekformanceof theforward slots laminarflow was notedgver the range investigated suggeststhat laminar flow is possible on swept (7 X to6 < Rc < 11 X 10 ). wings to much higher wingchord Reynolds numbers.

*NorthropCorp., Norair Div., Hawthorne, Calif. *NorthropAircraft, Inc., Hawthorne, Calif.

A-7. *Carmichael, B. H.: Surface Waviness Crite- A-9. *Stall, C. G.: PresentStatus of Production

-~ria for Swept and Unswept LaminarSuction Wings. Aircraft~ SurfaceWaviness atNorair. Northrop Northrop.NorairRept. No.NOR-59-438, BLC-123, Corp.,Norair Rept. No.NOR-59-444, BLC-126, Sep August1959, 19 pp. tember1959, 19 pp. N79-77134 N79-77136 Thisreport summarizes the available experimentaldata concerning the critical size of sur- Wavinessmeasurements were made on all models facewaviness on sweptand unswept laminar suction ofairframes currently in production at Norair to wings. A critical wave is definedas the minimum determinewhether products of standardfabricatlon size which preventsthe attainment oflaminar flow procedures were withinthe range ofwaviness tothe trailing edgeunder moderate suction. Data requirementsfor a BLC surface. A typical are shown which establishthe effect of the two requiredwaviness range for a medium sizehigh principalvariables, Reynolds number and relative subsoniclogistic airplane is 1/750 to 1/1500 (one wave length. A designchart is providedto enable partin 750 to one partin 1500). The majority of computation of the critical wave ratioover a wide specimensmeasured were grouped intothree catego- rangeof the variables. A small amount of infor- ries or typeswith their respective waviness mation is presented to show #e reductionin crit- ranges. ical wave ratio due to a groupof consecutive waves. A shortdiscussion of all pertinentvari- Waviness Range ables is includedin the text. 1. Thick skins 1/750 to 1/1500 Thesedesign charts apply to sinusoidal waves 2. Thin sfins over honeycomb 1/900 to 1/3000 on swept or unsweptwings inregions having a core closeapproach to distributedsuction (e.g., 3. Skinsover spars and skin 1/150 to 1/1000 multi-slotconstruction). They alsoapply to joints unsweptwings where the wave is in a nonsuction regionbut where strong flow acceleration exists. The survey showed thatCategory 3 (skins over spars and skin joints) failed to meet BLC waviness *NorthropCorp., Norair Div., Hawthorne, Calif. requirementsrange.

fNorthrop Corp., Norair Div.,Hawthorne, Calif. A-8. *Bacon, J. W., Jr.; *Tucker,Virginia L.; and 'Pfenninger, W.: Experimentson a 30° Swept 12 PercentThick Symmetrical LaminarSuction Wing in A- 10. *Pfenninger, W. : PreliminaryDesign Studies the 5- by 7-FOOt IJniversity ofMichigan 'Tunnel. of LargeLnw Drag BLC Long mduranceAirplanes. NorthropNorair Rept. No.NOR-59-328, BLC-119, NorthropCorp., Norair Rept. No. NOR-59-613, August 1959, 62 pp. BE-127, December 1959,64 pp.

67 APPENDIX

N79- 77 137 N79-77139

Generaldesign, propulsion, and general aero- Low dragboundary layer suction experiments dynamic considerationand preliminary design onan ogive cylinder were conducted at the Arnold calculations are made. An exampleof a low drag EngineeringDevelopnent Center Supersonic Tunnel longendurance airplane is worked-outbased on E-1 at Tullahoma,Tennessee, at Mach numbers2.5, resultsof the study. 3.0, and 3.5. The modelhad the same external dimensions as the onetested in 1958, but was *NorthropCorp., Norair Div., Hawthorne, Calif. equippedwith an improved suction system. A larger number ofclosely spaced slots approached continuoussuction to a betterdegree, and larger A-1 1. 'Worth, R. N. : Effectof Weathering on suction tubes permittedhigher suction coeffi- Typical Bonded BoundaryLayer Control Structure. cients.Full laminar flow and low drag coeffi- Northrop Corp., Norair Rept. No. NOR-59-608, cients were measuredup to Reynolds numbers BLC-128, January 1960,39 pp. % - 15 x lo6 at M = 2.5, % - 12 x lo6 at M = 3.0 and % - 7 x lo6 at M = 3.5. N79-77174 The houndarylayer development along the body The objects were to determinethe effects of was computed forseveral experimental suction and various climatic conditions on typicalboundary surfacepressure distributions and theresults layercontrol skin configurations with respect to were compared withthe test data. theoperational characteristics andmaintenance reqirementsof the suction system, and to evalu- *NorthropCorp., Norair Div., Hawthorne, Calif. ate thestrength characteristics of the adhesives, used to bond the test panels,after exposure to thevarious climatic conditionsof the test A-14. *Worth, R. N. : Effectof Environmental program. Exposureon Boundary Layer Control Surfaces and Operations.Northrop Corp., Norair Div. Rept. *NorthropCorp., Norair Div.,Hawthorne, calif. No. NOR-61-211,BLC-133, September1961, 31 pp.

N79- 77 154 A-12. *Pfenninger, W.; and *Bacon, J. W., Jr.: About the Developmentof Swept LaminarSuction The object was to determinethe effects of Wings With Full Chord Laminar Flow. Northrop exposure to various climatic environments on typi- Corp., Norair Rept. No. NOR-60-299,BLC-130, Sep- cal boundarylayer control skin configurations tember 1960, RevisedJanuary 1961,59 pp. (Pre- withrespect to theoperational characteristics sented at theTenth International Congress of andmaintenance rkquirements of the suction AppliedMechanics at Stresa,Italy, August- system. September1960. ) Steam cleaningof the surfaces every seven to N79-77138 tendays during operations in normal climatic conditionsshould prevent degradation of the suc- On aswept laminar suction wing spanwise tionsystem beyond a maximum of5 percent due to pressuregradients deflect the boundary layer air, contaminationof the slots andholes. which has lost part of its energy,toward the regionsof low static pressure. As a result, the *Northrop Corp., Norair Div., Hawthorne, Calif. flowpath of the boundary layer particles on a sweptlaminar suction wing differs from the potential flowstreamline, and a boundarylayer cross A- 15. *Groth,Eric, E. : Low Drag BoundaryLayer flowdevelops in the direction normal to the SuctionExperiments on a Flat Plate at Mach Nm-- potentialflow streamline. The boundarylayer bers 3 .O andy51, cross flow profiles in this direction show inflec- BLC-135, October 1961 (withFebruary 1963 tionpoints and are thusdynamically highly unsta- Addendum), 67 pp. bleagainst external disturbances at highwing chord Reynolds numbers. The questionconcerning N79-77141 the feasibility of fullchord laminar flow on sweptwings under cross flowconditions at high Low dragboundary layer suction experiments Reynoldsnumbers by means ofboundary layer suc- on a 41-inchlong flat plate were conducted at the tion is theobject of thisstudy. 40- by 40-InchContinuous Supersonic Tunnel A of the ArnoldEhgineering Development Center at *NorthropCorp., Norair Div.,Hawthorne, Calif. Tullahoma,Tennessee. The model was equippedwith 76 closelyspaced, fine slots arrangedin eight suctionchambers. Full length laminar flow was A-13. *Groth, E. E.: Low DragBoundary Layer obtained at M = 3.0 and 3.5 up to thehighest SuctionExperiments at SupersonicSpeeds on an possibletunnel pressures, resulting in length OgiveCylinder with 29 CloselySpaced Slotsi-~ Reynoldsnumbers of 25.7 X lo6and 21.4 x lo6, NorthropCorp., Norair Rept. No. NOR-61-162, respectively. The measureddrag coefficients (sum BLC-131, August1961, 69 pp. of wake and suctiondrag) were ofthe order of 28

68 I:

APPEWDIX

;@to 43 percent of theturbulence friction drag at NOR-64-114,(BLC-157) , NorthropCorp., June 1964, ,.,_ the same Reynoldsand Mach numbers. 207 pp. (Available to U.S. Gov't. Agenciesand "beir Con- The results of a calculationof the laminar tractors Only. ) boundarylayer development along the plate at typicalsuction distributions are compared916with AD 351 X67-88932 the test data. (Contract N& 61-0413-C) *Northrop Corp., Norair Div., Hawthorne, Calif. NorthropCorp., Hawthorne, Calif.

A-16. *Walz, A.: ApproximationTheory for Bound- aryLayer Suction Through IndividualSlits. NASA A-20. *Gross, L. W.; and*Pfenninger, W.: Experi- "-75384, May 1979, 51 pp. mentaland Theoretical Investigation of a Reichardt Body ofRevolution with Low Drag Suction Translation of "Naeherungstheoriefuer in the NASA-Ames 12 ft.Pressure Wind Tunnel. Grenzschichtabsaugungdurch Einzelschlitze," NASA CR-158413. Northrop Corp. Rept. No. Rept. No. D-184, June 1962. NOR63-46, BLC-148. July 1963,134 pp.

N62-16345 (German form) N78-77795 N79-23910 (Englishtranslation) Fulllength laminar flow with very low fric- The basic conceptsof influencing boundary tion andequivalent total drags was maintained on layers are summarized, especiallythe prevention an 8 to 1fineness ratio Reichardt body ofrevolu- of flowdetachment and the reduction of frictional tion of12-foot length by means ofboundary layer resistance. A mathematicalanalysis of suction suctionthrough 113 fine slots u to a length through a slit is presented, two parameters,for Reynolds number % = 57.76 x 10t . The lowest thicknessand for shape of theboundary layer, coefficient of equivalenttotal drag (based on beingintroduced to specify the flow's velocity body wettedarea and including the equivalent profilebehind the slit. An approximationof the suctiondrag) at anangle of attack a = Oo was shapeparameter produces a usefulformula, which C = 2.63 x at % = 57.76 x lo6with a can be used todetermine the most favorableposi- Dt tion of the slit. An aerodynamicexample is corresponding total suctionflow coefficient given. (based on wetted area) C = 1.77 X This Qt *DeutscheVersuchsanstalt fuer Luft- und value of equivalent total drag is 12 percentof Raumfahrt, Institutfuer Angewandte Mathematikund thefriction coefficient of a turbulent flat plate Mechanik, Freiburg, West Germany at thislength Reynolds number. Contract NASw-3199. 'NorthropCarp., Norair Div.,Hawthorne, Calif. Sponsored by NASA. A- 17. *Rogers, 0. R.; *Curran, E. T. ; Wrobel, N. A.: Aero-AcousticAspects of Laminar Flow Control. ASC-TDR-62-718, Vol. I. In: 1962 Com- A-21. *Pfenninger, W. : About Some Flow Problems pendium of Symposium Papers,Vol. I, Sept.1962, inthe Leading Edge Regionof Swept Laminar Flow (X68-81601), pp. 11-40. (Available to U.S. Gov't. Wings. Northrop Corp. Rept. No. BLC- 160, July Agenciesand Their Contractors Only. ) 1964, 30 pp.

X68-81603 N79-77143

*AeronauticalSystems Division, Air ForceSystems Duringthe first phase of the X-21 flight Command, Brooks AFB, Texas. tests, fullchord laminar flow was observedonly inthe outer part of the 30° swept wingsof the X-21 airplane.Total pressure probes located at A-18. *Pate, S. R.; and*Deitering, J. S.: Inves- the wing trailing edgeclose to theouter edge of tigation ofDrag Reduction by Boundary-Layer Suc- theboundary layer, if it were laminar, showed a tion on a 36-Deg Swept Wing at M = 2.5 to 4 . ratherlarge loss in total pressurein the inboard AEDC-TDR-63-23, U.S. Air Force, Feb. 1963, areas of the wing, indicating the presence of a 33 pp. (Available to U.S. Gov'tAgencies and thickturbulent layer at the trailing edge and Their Contractorsonly.) hence of extensiveturbulent flow in the inboard wingregions. (This report discussesproblems X63-11101 concernedwith turbulence onlaminar flow swept wings. *ARO, Inc.,Arnold Air Force Station, Tenn. Contract AF40/600/-1000 *NorthropCorp., Norair Div., Hawthorne, Calif.

A- 19. Summary of Studies Leading to the Develop- A-22. *Lang, T. G.; and*Patrick, H. V. L.:Wind- ment of a Laminar Flow Torpedo. Final Rept. No. Tunnel Tests on a Porous Body WithSuction. U.S.

69 APPENDIX

Navy NAVWEPS Wpt.8528, NOTs TP 3529,1964, ing the wake drag for constant chord wingshave 42 PP- (Availableto U.S. Gov't.Agencies and beendescribed for small and large sweep angles, TheirContractors mly.) respectively. With certain'modifications, the method for large sweepangles (in excess of the AD358 692 X68-85165 Mach angle)has been made more general so that it may also be used to determinethe local drag *NavalOrdnance Test Station, ChinaLake, Calif. coefficient ofa tapered wing,and thelocal coefficients may then be integrated along the spanwisecoordinate in order to determine the A-23. *Kobashi, Y.; and*Onji, A.: An Experimen- overalldrag coefficient. The developmentand talInvestigation of StabilityCharacteristics of methodof using this more general wake correc- UnsteadyLaminar Boundary Layer. Rept. No. NAG tion is givenin this report. TR-65, 1964, 16 pp. (InJapanese.) *NorthropCorp., Norair Div., Hawthorne, Calif. N65-22096#

Inorder to determine a stability criterion A-25. fcarmichael, R. F.;and *Finwall, P.: Anal- ofsmall disturbances in a boundary layer with a ysis of theResults of theLaboratory Cuct Model time-dependentoutside flow, experimental studies Test forthe X-21A Laminar Flow Aircrsft. Rept. havebeen carriedout in a wind tunnel ofa No.NOR-65-303, NorthropCorp., Nov. 1965, 80 pp. 20 cm X 15 cm crosssection, in which theflow speed was forced to oscillate sinusoidally around N79- 75674 its mean value. A method hasbeen developed that pr.edicts the The resultsare summarized asfollows: slotperturbation velocity, Aw, existingat the intersection of the wing surface andsuction slot, The boundary layervelocity profiles and giventhe spanwise duct sound pressure PD, and their stability characteristics vary with the thepertinent geometric and flow parameters. The phase of theoutside flow, and arerelated to method hasbeen empirically derived and qualita- unsteadinessparameters AU/U, and ws/Um. As tivelysubstantiated by theoretical methods. The faras these parameters are small, the stability result is presentedin terms of the mean, orbest of thedisturbances is relatedto the instanta- estimate;the probable error, or the 50% probabil- neousboundary layerprofiles. ity limits; and theupper 95%confidence limit assumingnormal distributionabout the mean of all 'NationalAerospace Laboratory, Tokyo, Japan test data.

The test resultsalso disclosed the existence A-24. *Goldsmith,John: A SuggestedProcedure for ofa disturbance in the suction slot that appears Determiningthe Wake Drag ofHighly Swept Wings by to be afunction of theslot flow. The existence Means of Simple Wake Measurements.Northrop .Fept. of thisdisturbance in a highstreanwise flow such No.NOR-65-285, BLC-165., October1965, 36 pp. as would occur in flighthas not beenconfirmed.

N79-77145 *NorthropCorp., Norair Div., Hawthorne, Calif.

Inlaminar flow control experiments, measurements arenormally made of the boundary lsyerin A-26. *Bacon, John W., Jr.; and*Pfenninger, W.: orderto evaluate the wake drag.This wake drag TransitionExperiments at theFront Attachment is thenadded to theequivalent suction drag in Lineof a 45O Swept Wing witha Blunt Leadinq orderto determine the effective skin friction Edge. AFFDL-TR-67-33, June1967, 43 pp.Final drag. The boundary layerprofile is measured by Rept. Feb.-Dec.1966. (Availableto U.S. Gov't. means of a total headrake and for two-dimensional Agenciesand Their Contractors Only.) unswept airfoils the wake drag may be determined from the momentum thickness of this profile by AD-818 962 X67-23005 conventional means. When, however, thetrailing edge is sweptthe momentum thickness(determined *NorthropCorp., Norair Division, Hawthorne, from the streamwise boundary layerprofile) cannot Calif. be used by itselfto determine the wake drag ContractAF33(657)-11618 accurateiy. A changeof procedure is requ'ireh since the 'mass flow rate on which the momentum deficit should be based mst be modified by the A-27. FinalReport on LFC Aircraft Design Data boundarylayer cross flow wheneversuch crossflow Laminar Flow ControlDemonstration Program. is present.Cross flow components will normally NorthropCorp., NOR-67-136, June 1967,415 pp. occurwhenever pressure gradients are present on a (Available to U.S. Gov't.Agencies and Their Con- swept wing and larger Sweep anglesgenerally tractors Only. ) resultin greater cross flow and larger correction factorsfor the wake drag.Methods fordetermin- AD 819 317 X67-22964

70 APPENDIX

This is a revision of Report NOR 61-141, A-30. *Vasudeva, B. R.: Boundary-Layer Instabil- "Laminar Flow ControlDemonstration Program, Final ity Experimentwith Localized Disturbance. Jour- Report - LFC Design Data," Contract AF nalof Fluid Mechanics, vol. 29, pt. 4. pp. 745- 33(600)-42052, April 1964. 763, 1967.

NorthropCorp., Hawthorne, Calif. Laminarboundary layer on a flat plate with (Contract AF 33(657)-13930) zeropressure gradient was excited by a solitary three-dimensionaldisturbance. The growthof the disturbance was studiedusing a 10-channellinear- A-28. *Beasley, J. A. : Some Notes on the Design ized d.c.-coupledhot-wire system. The develop- of Swept Wings for Laminar Flow Aircraft. Tech. ment of thedisturbance flow field was studiedand Rept. 67169, British R.A.E., July 1967,34 pp. comparedwith theory by Criminale hi Kovasznay (Available to U.S. Gov't.Agencies and Their Con- (1962). The experimental results indicate a tractors Only. ) departurefrom the theory on accountof the sim- plifyingassumptions made inthe theory. Certain 8 22 711 AD 822 1 133 X68- 1 new results were also obtained.

*Royal AircraftEstablishment, Farnborough, *Dept. ofMechanics, The JohnsHopkins Univ., England Baltimore, Md.

A-29. *McCauley, William D., ed.: Boundary Iayer A-31. *Kurn, A. G.: A SuctionControl System for TransitionStudy Group Meeting, July 11-12,1967. the BoundaryLayer Developed Along a Cylinder. Volume I1 - Sessionon Boundary Layer Stability. Tech. Memo. Aero. 1090, British R.A.E., Aug. 1968, BSPTR-67-213, Volume 11, U.S. Air Force, Aug. 28 pp. (Available to U.S. Gov't. AgenciesOnly.) 1967, 225pp. (Available to U.S. Gov't. Agencies andTheir Contractors Only.) X69- 15349

364 X67-23560 AD 820 364 *Royal Aircraft Establishment,Farnborough, England The followingpapers are containedin this volume:

Mack, Leslie Y. : Numerical Solutionsof A-32. *Morkovin, M. V.: Mechanicsof Boundary CompressibleBoundary Layer Stability, LayerTransition, Part 2: Instability andTransi- pp. +1 - 9-22. tion to Turbulence.VKI-Lecture-Series-3- Part 2, 176 pp. DCAF-FOO2628.Von Karman Inst. Kendall, James M., Jr.: SupersonicBoundary forFluid Dynamics,Rhode-St.-Genese, Belgium. Layer StabilityExperiments, pp. 10-1 - 10-8. N79-31530#

Brown, W. Byron: Improvements in Compress- Instability and transition fromlaminar to ibleSolutions of Stability Theory, pp. 11- turbulentshear layers is discussed.Topics 1 - 11-16. includeadvances in understanding the transition andcontradictions in transition research. Tran- Donaldson, Coleman duP.: andSullivan, sitioncorrelations for hypersonic wakes, three Roger D.: A Computer Studyof an Analyti- dimensionalboundary layers, laminar suction cal Model ofBoundary Layer Transition, wings,heat transfer and boundary layer transi- pp. 12-1 - 12-36. tion, andReynolds number effects are covered.

Reshotko, Eli: Stability Theory as a Guide *Martin Co., Baltimore, Md. to theEvaluation of Transition Data, pp. 13-1 - 13-22. A- 33. *Bacon, John W. , Jr - ; *Goldsmith, John ; and Nagel, A. L.: Compressible BoundaryLayer *Gross, Lloyd W. : Effectof Slot Configuration Stability by Time-Integrationof the andDisturbances From Slot or Environmenton Lami- Navier-StokesEquations, and an Extension nar Flow Vehicles. NCIr68-46RI Northrop Corp. of Emmons' TransitionTheory to Hypersonic Lab., July 31,1968, 143 pp. (Available to U.S. Flow, pp. 14-1 - 14-62. Gov't.Agencies and Their Contractors Cmly.)

Van Driest, E. R.; and Blumer, C. B.: Bound- AD851246 X69- 16041 aryIayer Transition onCones and Spheres at SupersonicSpeeds - Effects of Roughness *Northrop Corp., Hawthorne, Calif. andCooling, pp. 15-1 - 15-30. Contract ~00017-67-C- 11 12

*AerospaceCorp., San Bernardino, Calif.

71 APPENDIX

A-34. *Eppler, R.: laminarAirfoils for Reynolds A-36. *Craik,Alex D. D.: Non-LinearResonant Numbers Greater Than 4 X IO6. Boeing CO., Instabilityin BoundaryLayers. Journal of Fluid Seattle, Wash., Officeof International Cpera- Mechanics, vol. 50, part 2, 1971, pp. 393-413. tions.Translation into English from German Report AVA-67-A-62, B-819-35; April 1969,32 pp. A72-13160

A70- 10930 (Original German) Investigationof resonant triads ofTollmien- N69-28178# (Translation) Schlichting waves in an unstable boundarylayer. The triads considered are thosecomprising a two- Laminar airfoils, which means airfoils with dimensional wave and two oblique waves propagating the highestpossible drag gain by laminarboundary at equaland opposite angles to the flow direction layerswithout suction, have been examined thor- andsuch that all three waves havethe same phase oughlyin the region of smaller Re numbers. It is velocityin the downstream direction. Forsuch a time to report onghe gainspossible in the region resonanttriad remarkably powerful wave interac- above Re = 4 x 10 . !Ibe NACA airfoils which are tionstake place, which may cause a continuousand now over 20 yearsold, are considered as a point rapidtransfer of energy from theprimary shear ofdeparture. We proceed at firstpurely theore- flowto the disturbance. It appearsthat the tically, in a way whichhas already been success- oblique wavescan grow particularly rapidly and it fulfor smaller Re numbers. It couldbe seen that is suggestedthat such preferential growth may be keeping a boundarylayer laminar is not so diffi- responsiblefor the rapid development of three- cultin the region of smaller Re numbers if one dimensionalityin unstable boundary layers. The buildsprecision wings. The most difficult pro- non-linearenergy transfer primarily takes place blem lies herein avoiding laminar separations and inthe vicinity of the critical layer where the so-called local separationbubbles. In the Re downstreampropagation velocity of the waves number regionunder discussion this problem does equalsthe velocity of the primary flow. practicallynot play any ro e at all andany measurementswith Re = 4 x lo‘, wheresuch “bubbles” *Dept. ofApplied Mathematics, St. Andrews Univ., wouldhave had any effect, are not known to the St. Andrews, Scotland author had therenot beenvery sudden and very steeppressure increases. These however, are not appropriatefor reasons of flightcharacteristics. A-37. *East, L. F. : SpatialVariations of the The boundary layertransition is hereof the BoundaryLayer in a Large Low-SpeedWind Tunnel. utmostimportance. A reliabletransition crite- AeronauticalJournal, vol. 76,Jan. 1972, rion is thereforeof considerable importance for a pp.43, 44. theoreticaltreatment. A72- 1906 1 Note: The original German report is listed as #491 in NASA RP-1035. Experimentalstudy of boundary layer varia- tionscaused by fitting screen insets in wind *Stuttgart Univ., West Germany tunnels. The resultsobtained indicate that fittingscreens can remove spatialvariations of the boundary layerflow in the working section of A-35. *Struminskii, V. V.; *Filmonof M. L.; and thetunnel and thatthe dependence of theflow *Glushko, G. S. : Turbulent Flows (Selected Arti- upon thescreens in the settling chamber is as cles) - Stabilityof LaminarFlows and Bo~unda-ry greatin large as it is insmall tunnels. LayerTransition. (Translation into Ehglish by ForeignTechnology Div. AFSC, Wright-Patterson *Royal AircraftEstablishment, Farnborough, AFB). MOSCOW, 1970. England

Am754323 N74- 10344# A-38. *Struminskii , V. V. : Laminar Flow Stability A series of articles discussturbulent Problemsand theTransition to Turbulent Flow. flows. The overallproblem, the stability of FluidMechanics - SovietResearch, vol. 1, NO. 2, laminarflow, and transition to turbulentflow are Mar.-April1972, pp. 121-134. (A SurveyPaper.) discussed. Diagram equationsfor the degeneration of turbulence,and calculations of pressure and A72-37468 (English) velocityfluctuations in the boundary layer are A71-15602 (Russian) followed by articles on thekinematic characteristics of a turbulentflow during steady motion, An analysis is givenof the results of theo- pressurefluctuations on theboundary of a turbu- retical studiesusing the linear theory ofhydro- lentflow, turbulent flows in jets andducts, and dynamic stability. The needfor careful experi- theturbulent mixing of free jets. mentalverification of the deductions from linear theoryin the development of a non-lineartheory *Akademiia NaukSSSR, InstitutTeoreticheskoi i is shown. A critical analysis is made of the PrikladnoiMekhaniki, Novosibirsk, USSR existing attempts to construct a non-lineartheory

72 APPENDIX $- ofhydrodynamic stability. ?he author's non- windtunnels. The maximum soundpressure level in .&, linear theory unambiguously defines the nature of the 12-foottunnel was 146 dB at a Mach number of thedevelopnent of perturbations in a laminar 0.6 fornear atmospheric stagnation pressure. flow.Based on thistheory, a qualitativepicture Sound pressurelevels were about13 to 15 dB lower is givenof the transition from laminar to turbu- forequivalent stagnation pressures in the 9- by lent flow. 7-fOOt supersonic wind tunnelthan in the tran- sonicfacilities. The slots and the plenum 'Akademiia Nauk SSSR, InstitutTeoreticheskoi i chambersurrounding a transonic test sectionhave Prikladnoi Mekhanik,Novosibirsk, USSR beenidentified as thesource of the mst prom- inentpeaks whichoccur in the power spectral density measurements in transonic wind tunnels. A-39. *Burnel, S. ; and*Gougat, P. : Study of the Comparisonof results of a model in the wind Developmentof Natural Instabilities in a Laminar tunnel and infree flight provides an appraisal BoundaryLayer inIncompressible Flow. NASA of theeffects of tunnel background noise. .I"76560, June1981, 7pp. Translation into mglish by scientificTranslation Service, Santa *NASA, Ames ResearchCenter, Moffett Field, Calif. Barbara,Calif. from Comptes Rendus, Serie A - Science I Math., vol. 2,no. 16, April 17,1972, pp. 1251-1254. A-41. *Dougherty, N. S., Jr; and**Steinle, F. W.; Jr.: TransitionReynolds Number Compari- N81-27432X (English) sonsin Several Major TransonicTunnels. AIAA 8th A72-29784 (French) Aerodynamic TestingConference, Bethesda, Md., July 8-10,1974. Natural instabilities which are created in a laminarboundary layer consist of intermittent AIAA-74-627 A74-36048# wave trains. The spectral analysisof these fluctuations makes it possible to localize them in Boundary-layertransition and test section terms of frequencyand to isolate theirspectrum environmentalnoise data were acquiredin six ofamplitude modulation. The variationin terms majortransonic wind tunnels as a partof a of abscissavalue and ordinate value of these broadercorrelation of the effect of free-stream instabilities is compared withthe results derived disturbances on transitionReynolds number. The from thesolution of the Orr-Sommerfeld equation. data were takenat comparative test conditions on a sharp, smooth 10-deg included-anglecone. It NASW-3198 (Translation) was found that aerodynamicnoise sources within the test section were the dominantsources of *CNRS, Laboratoire d' Aerothermique, Meudon, Hauts- unsteadinessand that transition Reynolds number de- Seine, France provided a good indicator for theresulting degra- dationin flow quality. Amplitudes, frequency composition,directivity, and origin of these A-40. *Dads , Jules B., Jr .; and*Hanly , disturbances are described. Richard D.: Evaluationof Transonic and Super- sonic Wind-Tunnel Background Noise and Effects of *ARO, Inc.,Wnold Air ForceStation, Tenn. ~~ ~~ ~~ ~. ~~ SurfacePressure Fluctuation Measurements. Pre- **NASA, Ames ResearchCenter, Moffett Field, sented at the AIAA 7th Aerodynamic TestingConfer- Calif. ence,Palo Alto, Calif., Sept. 13-15, 1972, 8 pp.

AIAA-72- 1004 A72-41588# A-42. *Varner, M. 0.: Noise Generationin Tran- sonicTunnels. AIM 8th Aerodynamic "%?stingCon- An investigationof wind-tunnel background ference,Bethesda, Md., July 8-10,1974, 13 pp. noisein the Ames ResearchCenter 12-foot pressure windtunnel, the 11- by 11-footand the 14-foot AIAA-74-633 A74-35397# transonic wind tunnels, and the 9- by7-fOOt supersonic wind tunnelhas been made. The data, Inan attempt to better understand the noise which represent a frequencyrange from 10 Hz to environmentin transonic tunnels, noise generation 20 kHz, havebeen analyzed in the formof mechanisms were isolatedand studied. The noise (1)broadband sound pressure levels and root-mean- environment in the test section is separatedinto square fluctuations of pressure coefficient, threedistinct parts: thenoise due to jet flow (2) power spectra inboth dimensional and non- through the porous walls, a wall hole-tunnel reso- dimensionalform, and (3) cross spectra andphase nance phenomenon, andthe turbulent boundary layer angle,yielding narrow bandconvection velocities. onthe test section walls and in the diffuser. The surveysindicated a maximum broadbandsound Each part is analyzedseparately for the effects pressurelevel of 155 dB at maximum tunnelstagna- ofaerodynamic and geometric flow constraints on tionpressure in the 11- by 11-foottransonic thefrequency and power characteristics. The tunnel.For equivalent stagnation pressures, the contributionof each of the models to the fluctu- soundpressure levels wereapproximately the same ating pressure level is also examined. in both the 11- by 11-footand 14-foot transonic *ARO, Inc., Arnold Air ForceStation, Tenn.

73 APPENDIX

A-43. *Pfenninger, W.; and*Syberg, J.: Reduction bances create problems Mcause the instrumentation of AcousticDisturbances in the Test Section of senses them in addition to thefluctuations gener- Supersonic Wind Tunnels by Laminarizing Their ated by theaerodynamic flow over wind-tunnel Nozzleand Test Section Wall BoundaryLayers by models. Calibrationsof 25 facilities show that Means ofSuction. NASA CR-2436, Nov. 1974, theamplitudes of the background fluctuations are 305 pp. excessive.In porous-wall facilities, one noise source consists of porous-walledgetones that are N75- 12977# generated by the passage of air overthe holes. A flow model is developed that yields the frequen- The feasibility of quiet,suction laminar- cies ofthese oscillations. Test section boundary ized,high Wynolds number (Re) supersonic wind layers and hole configurationsgovern the occur- tunnelnozzles was studied.According to nozzle renceof these fluctuations. In slotted-wall wall boundarylayer development and stability facilities, a noisesource is theslotted-wall studies,relatively weak area suctioncan prevent shearingcaused by the air flowingalong the open- amplifiednozzle wall TS (Tollmien-Schlichting) ings.In both types of wind tunnels,other flow boundarylayer oscillations. Stronger suction is mechanisms also causedisturbances, and these needed in andshortly upstream of the supersonic phenomena are described.Noise-reduction methods concavecurvature nozzle area to avoidtransition are outlined which will providevalid unsteady due to amplified n; (Taylor-Goertler)vortices. aerodynamicresults. !lb control TG instability,moderately rapid and slow expansionnozzles require smaller total suc- *Chrysler Corp., Huntsville, Ala. tion rates thanrapid expansion nozzles, at the Contracts NAS8-27503 and NAS8-30517 cost oflarger nozzle length Re andincreased TS disturbances. The total suction mass flow ratios forthe laminarization of high Re supersonic air A-45. *Roos, F. W.: SurfacePressure and Wake nozzlesincrease from nis/mo = 0.005 at M* = 3 Flow Fluctuationsin a SupercriticalAirfoil Flow- (test section) to 0.0105 at M* = 9. Nozzle wall field. AIAA 13thAerospace Sciences Meeting, coolingdecreases TS oscillation; TG instability Pasadena,Calif., Jan. 20-22, 1975, 10 pp. in the concavecurvature region, though, may be worse. Due to smaller nozzlelength A75-Re and AIAA-75-66 18288# Goertlerparameters, M* = 9 heliumnozzles requirehalf as much suctionfor their laminariza- Nonsteady featuresof a Whitcombtype super- tion as M* = 9 air nozzlesof the same UfD*/v* critical airfoil flowfield were studied in a (test section) . Boundary layercrossflow instabi- series oftransonic wind tunnelexperiments. Data lity on the side walls oftwo-dimensional high Re consistedof mean and fluctuating pressures on the supersonicnozzles due to streamlinecurvature airfoil and in the free stream, velocityfluctua- requiresstrong local suction to avoidtransition. tions in the wake region,and airfoil vibrations. Nozzle wall surfaceroughness is critical in the Fluctuationdata were analyzedstatistically for throat area, especially at high M*, butnot in intensity,frequency content, and spatialcoher- the downstreamnozzle region. Allowable surface ence:variations in these parameters were corre- roughness inthe throat area of a M* = 9 helium latedwith changes in the mean airfoil flowfield. nozzle is five times largerthan for a comparable Surfacepressure fluctuation intensity was influ- M* = 9 airnozzle. Test section mean flow irre- encedprimarily by the location andmotion of the gularities can be minimizedwith suction through upper-surfaceshock, the existence of separation, longitudinalor highly swept slots (sweptbehind and(downstream of theshock) the developmentand local Mach cone) as well as finelyperforated upstreampropagation of "shocklets." Power spec- surfaces(hole spacing < subsonicnozzle wall tra ofpressure fluctuations showed characteris- boundarylayer thickness). Longitudinal slot tics differences upand downstream of the shock. suction is optimized when thesuction-induced Chordwiseand spanwise coherences were consider- crossflowvelocity increases linearly with surface ablyreduced in the presence of separation. Down- distancefrom the slot "attachmentline" toward wash fluctuations at the edgeof the wake were the slot (throughsuitable slot geometry). Suc- noticeablyaffected only by the developmentof tionin supersonic blowdown tunnels may be oper- trailing-edgeflow separation. ated by one or several individual vacuum spheres. *McDonnell DouglasResearch Labs., St. Louis, Mo. *BoeingCommercial Airplane Co., Seattle, Wash. , Researchsupported by McDonnell-Douglasand NASA Contract NASw-2359

A-46. *Saric,William S.; and *Navfeh. Ali H.: " A-44. *McCanless, G. F., Jr.; and *Boone, J. R.: Noise Reductionin Transonic Wind Tunnels. Acous- VPI-875-5, Feb. 1975, 27 pp. tical Societyof America, Journal,vol. 56, Nov. 1974,pp. 1501-1510. AD-A006918 N75-22654#

A75- 14385 The spatial stability oftwo-dimensional incompressibleboundary-layer flows is analyzed by The phenomena ofbackground noise generation usingthe method of multiple scales. The analysis intransonic wind tunnels are analyzed.In takesinto account the streamwise variationsof unsteadyaerodynamic tests, background distur- the mean flow,the disturbance amplitude, and the

74 APPENDIX ,; ,; i ... .L. wavenumber. The theory is applied to theBlasius wall tunnelswith 60-deg inclinedholes were iso- and the Falkner-Skanflows. For the Blasius flow, lated andstudied. 'Ihe noiseenvironment inthe thenon-parallel analytical results are in good test section is separatedinto three distinct agreementwith the experimental data. The results parts:the noise due to jet flowthrough the show that thenon-parallel effects increase as the porous walls, a wall hole-tunnelresonance pheno- pressuregradient decreases. menon, and theturbulent boundary layer on the test section walls and inthe diffuser. Each part *VirginiaPolytechnic Inst. and State Univ., is analyzedseparately for the effects of aero- Blacksburg, Va. dynamicand geometric flow constraints on the Contract NOOO14-72-A-0136-0002 frequencyand power characteristics. The contri- Preparedin cooperation with Sandia Labs, butionof each of the acoustic models to the test Albuquerque, N. Mex. sectionfree-stream fluctuating pressure level is also examined.

A-47. *Nagel, A. L.; *Alford, W. J., Jr.; and *ARO, Inc.Arnold Air ForceStation, Tenn. **Dugan, J. F. , Jr.: Future Long-Range Trans- ports - Prospects for Improved Fuel Efficiency. NASA!"X-72659, Feb.1975, 18 pp. A-49. *Kulfan, R. M.; and *Howard, W. M.: Appli- cation of Advanced AerodynamicConcepts to Large N75- 173391 SubsonicTransport Airplanes. Final Tech. Rept., October 1974-September1975; D6-75748; A status report is provided on currentthink- AFFDGTR-75-112; Nov. 17,1975, 117 pp. ing concerning potential improvements in fuel efficiency and possiblealternate fuels. Topics ADA019956 N76-251591 reviewed are: historicaltrends in airplane efficiency;technological opportunities including A preliminarydesign study has been made to supercriticalaerodynamics, vortex diffusers, identifythe performance advantages obtained when composite materials, propulsionsystems, active advancedaerodynamic technology aircraft are used controls, andterminal-area operations; unconven- to performsubsonic military airmissions requir- tionaldesign concepts, and hydrogen-fueled inglong range (10,000 mi) or highendurance airplane. (24hr) with heavy payloads (250,000 lb and 400,000 lb,respectively). The studyconsisted of *NASA, langleyResearch Center, Hampton, Va. two phases;the first included evaluating the **NASA, Lewis ResearchCenter, Cleveland, Ohio performancebenefits by individuallyapplying variousadvanced aerodynamic concepts and recommending areas where additionalresearch and A-48. *Varner, M. 0. : NoiseGeneration in Tran- development work are necessary. The secondphase sonic Wind mnnels.Final Report, June 1973-June includedconfiguring integrated advanced tech- 1974. AEDC-TR-74-126, April, 1975, 40 pp. nologyaircraft that incorporated the most promisingcompatible aerodynamic concepts. AD-A007688 N75-23614# Comparisons were made withconventional aerc- dynamictechnology configurations designed for Inan attempt to determinethe parameters similar missions. characterizingthe noise environment in transonic tunnels,noise-generating mechanisms forporous- *Boeing Commercial Airplane Co., Seattle, Wash. Contract F33615-75-C-3013

75 AUTHOR INDEX

Citation number Citation number

AGAFtD ...... 36 Dagenhart. J . R ...... 68. 147. 263. 275 Aihara. Y ...... 216 Davis. R . E ...... 217.250. 266. 277 Alford. W . J., Jr ...... A-47 Deitering. J . S ...... A-10 Allen. J . B ...... 298 Demetriades. A ...... 223 Allison. D . 0 ...... 68 Denning. R . M ...... 11 Althaus. D ...... 268 Dods. J . B .. Jr ...... A-40 Anderson. E . C ...... 76. 80. 128. 274 Donaldson. C . duP ...... A-29 Applin. Z . T ...... 248 Dougherty. N . S., Jr ...... 43. 157. 179. A-41 Arata. W . H., Jr ...... 123 Douglas Aircraft Co...... 19 Dugzn. J . F., Jr ...... A-47 Bacon. J . W., Jr ...... A-8. A-12. A-26. A-33 Durao. D. F . G ...... 152 Barger. R . L ...... 112 Batill. S . M ...... 172 East. L . F ...... A-37 Bauer. F ...... 5 Ecklmd. R . C ...... 285 Beall. R . T ...... 185 Econ. Inc ...... 20 Beasley. J . A ...... A-28 Eggleston. B ...... 117 Beckmann. M ...... 5 Eiseman. P . R ...... 78 Beckwith. I . E ...... 227 Elfstrom. G . M ...... 117 Bennett. J . A ...... 14. 15. 297 El-Hady. N . M ...... 91. 102. 132. 155. 159.168 Benney.D . J ...... 58 191. 231. 254. 255. 256. 257 Biringen. S ...... 272 258. 293 Blackwelder. R . F ...... 120 Eppler. R ...... 75. 118. 119. 139. 198 Blumer.C . B ...... A-29 210. A-34 mbbitt. P . J ...... 74. 229.288 Etchberger. F . R ...... 14. 15 BoeingCommercial Airplane Co ...... 101. 109. 110127. 284 Fasel. H ...... 21. 139 Bogdevich. V . G ...... 203 Fernald. W . W ...... 55 Bohn. A . J ...... 116 Ferrill. R . S ...... 14. 15. 27 Bonner. T . F., Jr ...... 55 Filmono. M . L ...... A-35 Boone. J . R ...... A-44 Finson. M . L ...... 42 Bower. R . E ...... 260 Finwall. P ...... A-25 Bozatli. A . N ...... 95. 129. 134. 153. 177 Fisher. D . F ...... 66.91. 157 Bradley. E . S ...... 50 Floryan. J . M ...... 135. 192. 212. 276 Braslow. A . L ...... 92. 282 FOSS. R . L ...... 34 Brooks.C . W., Jr ...... 176 Frisbee. L . E ...... 46 Brooks. J . D...... 175. 176. 241 Brown. P . W ...... 261 Garabedian. P ...... 5 Brown. W . B ...... A-29 Gaster. M ...... 206 Brykina. I . G ...... 208 Gazley. C., Jr ...... 220 Burnel. S ...... A-39 Geddes. J . P ...... 13 Bushnell. D . M ...... 131. 141.183 Geller. E . W ...... 158 Byon. W ...... 295 George-Falvy. D ...... 69. 87. 108 Gershbein. E . A ...... 208 Campbell. R . L ...... 244. 278 Gibeling. H. J ...... 78 Canu. M ...... 2 Gibson. J . S ...... 97 Carmichael. B . H ...... 264. A-6.A-7 Gilbert. B ...... 90 Carmichael. R . F ...... A-25 Gladwell. I ...... 63 Carter. J . E ...... 28 Glushko. G . S ...... A-35 Cebeci. T ...... 49. 105. 182 Goglia. G . L ...... 167. 254 Chan. Y . Y ...... 186 Goldsmith. J ...... A-5. A-24. A-33 Chen. J . L . S ...... 290 Gougat. P...... 39. A-39 Christopher. D ...... 245 Gratzer. L . B ...... 69 Coleman. W . S ...... A-2 Grauer-Carstensen. H ...... 149 Cornelius. K . C ...... 214 Gregorek. G . M ...... 29 Cotta. R ...... 162 Gross. L . W ...... A-20. A-33 Cousteix. J ...... 130 Groth. E . E ...... A-13. A-15 Coy. P . F ...... 261 Craik. A . D . D ...... A-36 Hage. R . E ...... 62 Crane. R . I ...... 152 Hankey. W . L ...... 294 Creel. T . R., Jr ...... 227 Hanly. R . D ...... A-40 Croom.C . C ...... 225 Harris. J . P...... 29 Cunnington. G . R., Jr ...... 207 Harvey. W . D ...... 79. 136. 209. 229. 247 Curran. E . T ...... A-17 273 .279

76 .

. Hawkins. w . M ...... 199 Malik. M . R ...... 190. 196. 230.253 Hefner. J . N ...... 131. 183 Mangiarotty. R . A ...... 116. 240 Herbert. 'Ih ...... 23 Martin. F ...... 39 Hodges. J ...... 103 Mask. R . L ...... 146.200 Hoffmann. M . J ...... 29 McCanless. G . F., Jr ...... A-44 Holdeman. J . D ...... 217. 266. 277 McCauley. W . D ...... A-29 Holmes. B . J ...... 225. 261. 280 McKinney. M . 0 ...... 237 Hopps. R . H ...... 46. 52 McQuilkin. F . T ...... 113.286 Hough. G . R ...... 143 Meade. L . E ...... 14. 15.27. 54. 125 Howard. W . M ...... A-49 Meier. H . U ...... 35. 77 Hussaini. M . Y ...... 160. 166 Mercer. 3 . E ...... 158 Meroney. R . N ...... 30 Jagger. D . H ...... 222 Migirenko. G . S ...... 248203 Jameson. A ...... 5. 158 Mikuta. V . I...... 203 3eng. M . C ...... 290 Miller. S . C ...... 11 Jenkins. M . W . M ...... 224 Mironov. B . P ...... 203 Jernell. L . S ...... I 84 Misra.. U . N ...... 94 30be. C . E ...... 7. 124 Mojola. 0 . 0 ...... 31 Johnson. D ...... A- 1 Molloy. J . K ...... 126 Johnson. M . L ...... 158 Montoya. L . C ...... 245 Jones. D . J ...... 117 Morkovin. M . V ...... 37. 83. A-32 Morris. P . J ...... 295 Kachanov. Yu . S ...... 47. 86 Mueller. T . J ...... 172 Kahawita. R . A ...... 30 Mungur. P ...... 137 Kaups. K ...... 49 Muraca. R . J ...... 65. 92 Kays. A . 0 ...... 27 Keefe. L . R ...... 111 Nagel. A . L ...... 72. A.29. A-47 Kelly. R . E ...... 44 Nagib. H . M ...... 142. 174. 289 Kendall. 3 . M., Jr ...... A-29 Nastrom. G . r) ...... 217. 266.277 Kirkinskiy. A . T ...... 180 Nath. G ...... 283 Klineberg. J . M ...... 6. 33. 53. 100 Nayfeh. A . H ...... 38. 81.85. 95. 104. 122 Klopfer. G . H ...... 166 129. 132. 134. 140. 151 Kobashi. Y ...... A-23 155. 159. 170. 177. 181 Kobayashi. R ...... 56 193. 194. 232. 233. 238 Kobets. G . F ...... 203 242. 249. 291. 296.A-46 Koegler. J . A., Jr ...... 150 Newman. P . A ...... 76. 80. 274 Kohama. Y ...... 56 Niehuis. R ...... 226 Kong. F . Y ...... 218. 270 Noggle. L . W ...... 124 Kopkin. T . J ...... 25 Novikov. B . G ...... 203 Korn. D ...... 5 Koziuk. G . S ...... 203 Obara. C . 3 ...... 261. 280 Kozlov. V . V ...... 47. 59. 86 Onji. A ...... A-23 Kramer. J . J ...... 6. 88 Orszag. S . A ...... 51. 58. 165. 171. 184. 196 Kreplin. H . P ...... 77 221.230. 253 Krishnaswamy. R ...... 283 Owen. F . K ...... 136.209. 213 Kuenzi. H . P ...... 5 Kulfan. R . M ...... A-49 Padhye. A ...... 85. 170.211. 233 Kurn. A . G ...... A-31 Pailhas. G ...... 130 Kutateladze. S . S ...... 24 Papenfuss. H.-D...... 226 Parmley. R . T ...... 207 Lang. T . G ...... A-22 Pate. S . R ...... 173. A-18 Lange. R . H ...... 50 Patrick. H . V . L ...... A-22 Leehey. P ...... 144 Payne. H . E ...... 9. 29 Lekoudis. S . G ...... 60. 107. 133. 164 Pearce. W . E ...... 71. 299 Leonard. R . W ...... 22. 89 Peigin. S . V ...... 208 Levchenko. V . Ya ...... 47. 59.86. 204 Petersen. Richard B ...... 281 Leventhal. L ...... 228 Peterson. 3 . B., Jr ...... 66. 91.274 Lindh. D . V ...... 26 Pfenninger. W ...... 48. 147. 239. A-6.A-8 Lockheed-Georgia Co ...... 202 A-108 A-12. A-20. A-21 Loehrke. R . I ...... 289 A-26. A-43 Lovell. W . A ...... 82. 98. 115 Philipp. V . Y ...... 197 Piatt. M ...... 236 Mabey. D . G ...... 16. 163 Poll. D . I . A ...... 41. 148 Mack. L . n ...... 106. 215. A-29 Pope. G . G ...... 99 MacDonald. I . S ...... 45 Povinelli. F . P ...... 6 Maddalon. D . V ...... 8. 18. 246. 28 1 Price. J . E ...... 82. 98.115 Maksimov. v . P ...... 59 Pride. J . D., Jr ...... 55. 247. 273 Pugh. P . G ...... 149

77 I . i- .

Quartero, C . B ...... 82. 98. 115 Tan.Atichat. J ...... 142. 174. 188. 289 Quast. A ...... 178 Tetianko. V . A ...... 203 puemard. C ...... 149 Thelander. J . A ...... 298 Thomas. A . S . TJ ...... 214 Ragab. S . A ...... 151. 156. 193. 194. 242 Tibbetts. J . G ...... 138 Reed. H . L ...... 147. 194. 232. 249.267 Trujillo. Bianca ...... 245 291. 296 Tucker. V . L ...... A-8 Reshotko. E ...... 228. A-29 Tumin. A . M ...... 180 Reynolds. G . A ...... 249. 271 . 287.292 Turriziani. R . V ...... 82. 98. 115 Rife. C . D ...... 25 Tuttle. M . H ...... 141 Riley. N ...... 259 Roache. P . J ...... 121 Van Driest. E . R ...... A-29 Rogers. K . H ...... A-3 Vaningen. J . L ...... 40 Rogers. 0. R ...... A-17 Varner. M . 0 ...... A-42. A-48 ROOS. F . W ...... A-45 Vasudeva. B . R ...... A-30 Rudnitskii. A . L ...... 59 Verma. A . K ...... 231. 293 Runyan. L . J ...... 108. 145 Volodin. A . G ...... 32 Ryzhenko. A . I ...... 96 Wagner. R . D ...... 9. 18. 22 Saric. W . S ...... 38. 135. 192. 249.276 Walz. A ...... A-16 287. 292. A-46 Washburn. G . F ...... 82. 98. 115 Schairer. E . T ...... 169 Wazzan. A . R ...... 220 Scheiman. J ...... 175. 237. 241. 243.265 Weeks. D. J ...... 103 Schetz. J . A ...... 218. 270 Weiss. D . I) ...... 26 Schrader. 0. E ...... 12 Welge. H . R ...... 298 Schuh. H ...... A-4 Whitfield. J . D ...... 43 Shamroth. S . J ...... 78 Wigeland. R . A ...... 142. 174 Shang. J . S ...... 294 Wilcox. D . C ...... 161 Sharma. V . P ...... 94 Wilkinson. S . P ...... 167. 253 Shcherbakov. V . A ...... 59 Williams. N . R ...... 252. 285 Shevell. R . S ...... 3. 93 Wilson. S . D . R ...... 63 Shtatnov. Iu . V ...... 203 Wilson. V . E ...... 187. 251 Sidorenko. N . V ...... 180 Winblade. R . L ...... 189 Singh. P ...... 94 Winoto. S . H ...... 152 Smith. A . M . 0 ...... 220.262 Winter. K . G ...... A-4 Solov'ev. A . S ...... 204 Worth. R . N ...... A-11. A-14 Somers. D . M ...... 75. 198. 210. 219. 234. 235 Wortmann. F . X ...... 268 Sonoda. T...... 216 Wray. A ...... 160 Srokowski. A . J ...... 51. 67 Wright. A . S ...... 114 Stack. J . P ...... 275 Wright. G . H ...... 11 Stainback. P . C ...... 136. 176. 209 Wrobel. N . A ...... A-17 Stall. C . G ...... A-9 Steers. L . L ...... 145. 205. 245 Yasinskiy. F . G ...... 96 Steinle. F . W., Jr ...... A-41 Yip. L . P ...... 261 Stern. J . A ...... 62 Young. n . R ...... 27 Stewartson. K ...... 105. 182 Struminskii. V . V ...... A-35. A-38 Sturgeon. R . F ...... 14. 15. 61. 70. 201 Sullivan. R . D ...... A-29 Swift. G ...... 137 Swinford. G . R ...... 10 Syberg. J ...... A-43

78 1. Report No. 2. GovernmentAccession No. 3. Recipient's Catalog No. NASA TM-84496 I 4. Title and Subtitle 5. Report Date LAMINAR FLOW CONTROL (1976-1982) - A SELECTED, August 1982 ANNOTATED BIBLIOGRAPHY 6. PerformingOrganization Code 534-01-13-06 7. Author(s) 8. Performing Organization Report No. Marie H. Tuttle and Dal V. Maddalon L- 15434

, 10. Work Unit No. 9. Performing Organization Name and Address

NASA Langley Research Center 11. Contract or Grant No. Hampton, VA 23665 . 13. Type of Report andPeriod Covered 2.Sponsoring Agency Name and Address Technical Memorandum

NationalAeronautics and Space Administration 14. SponsoringAgency Code Washington, DC 20546

5. SupplementaryNotes

6. Abstract

Laminar Flow Control (LFC) technologydevelopment has undergone tremendous progress inrecent years as focusedresearch efforts in materials, aerodynamics,systems, and structures havebegun to pay off. A virtual explosion in the number of research papers published on this subject has occurred since interest was first stimulated by the 1976 introduction of NASA's Aircraft Energy Efficiency Laminar Flow Control (ACEE/LFC) Program. The purpose of thisselected bibliography is to list available, unclassified laminar flow (both controlled and natural) research completed from abou 1975 to mid 1982. Some earlier pertinentreports are includedbut listed separately inthe Appendix. Reportslisted herein emphasizeaerodynamics and systems studies, but some structures work is also summarized. Aerodynamic work is mainly limitedto thesubsonic and transonic speed regimes.Because wind-tunnel flow qualities, such as freestream disturbance level, play suchan important role in boundary-layer tran sition, mch recent research has been done in this area and it is also included.

~ - ~- . Key Words(Suggested by Authorls)) 18. Distribution Statement Laminar flow control Unclassified - Unlimited Hybridlaminar flow Naturallaminar flow Tunnel disturbances/f luctuations Boundary-layer transition Subject Category 34 __ 3. SecurityClassif. (of this report) 20. SecurityClassif. (of this page) 21. No. of Pages 22. Price Unclassified I Unclassified 1 81 I A0 5

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