NASA Technical Memorandum 100289

Internal Fluid Mechanics Research on for Aerospace Propulsion Systems

__ (~ASA-T~-lOO289) IITEBUAL FLUID HECHBUICCS N88-15188 RESEARCR 01 SUPERCOUPUTEBS FOB ABflOSPACB PBOPULSIOI SYSTEHS (HASA) 17 p CSCL 20D Unclas G3/34 0119504

Brent A. Miller, Bernhard H. Anderson, and John R. Szuch Lewis Research Center Cleveland, Ohio

Prepared for the Third International Conference on Supercomputing-ICs '88 sponsored by the International Supercomputing Institute, Inc . Boston, Massachusetts, May 15-20, 1988 INTERNAL FLUID MECHANICS RESEARCH ON SUPERCOMPUTERS FOR AEROSPACE PROPULSION SYSTEMS

Brent A. Miller, Bernhard H. Anderson, and John R. Szuch

National Aeronautics and Space Administration, Lewis Research Center, Cleveland, Ohio 44135

Abstract. The Internal Fluid Mechanics Division of be routinely computed, the experimental data base the NASA Lewis Research Center is combining the key must expand to include not only surface-measurable elements of computational fluid dynamics, aerother- quantities, but also detailed measurements of fluid ,, ,, modynamic experiments, and advanced computational and thermal parameters throughout the flow regime of 2 technology to bring internal computational fluid interest. Also, the errors inherent in experimental mechanics (ICFM) to a state of practical applica- testing must be identified, understood, and rnini- tion for aerospace propulsion systems. mized in order to produce the high-quality, bench- mark data sets that are required for validation of The strategies used to achieve this goal are to (1) CFD applications codes and for use in developing pursue an understanding of flow physics, surface physical modeling data. heat transfer, and combustion via analysis and fun- damental experiments, (2) incorporate improved The process of conducting "benchmark" experiments understanding of these phenomena into verified that highlight one or more basic flow mechanisms and three-dimensional CFD codes, and (3) utilize state- tieing the experiments to analyses has had of-the-art computational technology to enhance the a long history at NASA Lewis [ll. The Internal experimental and CFD research. Fluid Mechanics Division of NASA Lewis is combining the key elements of computational fluid dynamics, This paper presents an overview of the ICFM program aerothermodynamic experiments, and advanced computa- in high-speed propulsion, including work in inlets, tional technology to bring internal computational turbomachinery, and chemical reacting flows. Ongo- fluid mechanics (ICFM) to a state of practical ing efforts to integrate new computer technologies, application for aerospace propulsion systems. such as parallel computing and artificial intelli- gence, into the high-speed aeropropulsion research The strategies used to achieve this goal are to (1) are described. pursue an understanding of flow physics, surface heat transfer, and combustion via analysis and fun- damental experiments, (2) incorporate improved INTRODUCTION understanding of these phenomena into verified three-dimensional CFD codes, and (3) utilize state- Computational Fluid Dynamics (CFD) is becoming an of-the-art computational technology to enhance the increasingly powerful tool for the aerodynamic experimental and CFD research. design of aerospace systems. This is particularly important in propulsion due to the lack of alterna- By focusing on specific portions of a propulsion tives for gaining insight into the complicated, system, it is often possible to isolate and study highly coupled fluid dynamics within modern propul- the dominant phenomena in order to gain the under- sion systems. standing needed to develop an accurate, predictive capability. As shown in Fig. 1, the NASA Lewis ICFM Improvements in numerical algorithms, geometric program is organized with Inlets, Turbomachinery, modeling, grid generation, and parameter modeling, and Chemical Reacting Flows as the main research as well as dramatic improvements in thrusts. processing speed and memory, are now allowing CFD researchers to address more complex configurations The development of an accurate, predictive capabil- and geometries, broader flight regimes, and new ity in propulsion CFD can only be accomplished if applications. These advancements are also permit- the numerical code development work and the experi- ting models and codes to be combined to solve mental work are closly coupled. As shown in Fig. 2, larger, more complex systems. each discipllne is dependent on the other for infor- mation and guidance. The insights gained through For CFD to be used with confldence In propulsion the experiments form the basis for new mathematical system design, it is necessary to verify and vali- models and codes. The resultant codes must be date existing and forthcoming CFD application codes tested by comparison of analytical and experimental with the best available experimental data. Because data, often leading to new test requirements. of the complexity of the aerodynamic flows that will

1 This paper presents an overview of the ICFM program tered some of the problems predicted by the com- in high-speed propulsion, which includes sustained puter analysis during testing. supersonic cruise, hypersonic to orbit, and advanced high thrust to weight core technology. CFD research Because the computer results were obtained early in activities in inlets, turbomachinery, and chemical the design process, it was possible to redesign the reacting flows are described along with ongoing inlet to incorporate boundary layer control devices efforts to integrate new computer technologies, in the vicinity of these predicted problems. Tests such as parallel computing and artificial intelli- of the redesigned full-scale iplet model will be gence, into the high-speed aeropropulsion research. conducted in the NASA Lewis 10xlO.supersonic wind tunne 1 . I ICFM RESEARCH THRUSTS To fully understand and visualize the massive Inlets amounts of data produced by supercomputer analyses, I one needs to employ some type of computer graphics With the availability of supercomputers, analyses . Figure 7 shows a researcher working are now being used in conjunction with experiments at a Silicon Graphics Iris workstation that is con- to understand the complex flow phenomena present in nected to the Numerical Aerodynamic Simulator (NAS) aircraft inlets. Inlet flows are highly three- computing network. In the figure, the researcher dimensional, often with regions of mixed supersonic is shown comparing computed surface oil flows in a and subsonic flow and containing steep gradients in glancing shock boundary layer interaction with the flow variables near shock waves and boundary results from an experiment at the identical flow layers. Detailed experiments and fast, large capac- condition. The use of three-dimensional visualiza- ity are required to resolve and accu- tion techniques is resulting in a better understand- rately compute these flowfields. ing of experimental results and the underlying physics. This is enabling the development of com- An example of integrated experiment and analysis is puter codes that can accurately predict detailed the development of an inlet for the Mach 5.0 cruise flow features thus increasing confidence in the use aircraft shown in Fig. 3. This vehicle was proposed of the codes for propulsion system design. by Lockheed to the Air Force as a successor to the SR-71. The aircraft has wing-mounted ramjets to Turbomachinery provide the required propulsion at Mach 5.0. The proposed design has been studied for several years Current research in turbomachinery CFD at NASA using both computer simulations and wind tunnel Lewis is focused on providing verified computer tests of sub-scale inlet models. A picture of one codes for the agressive design of advanced compo- such model is shown in Fig. 4, mounted in the NASA nents for the next century's propulsion systems. Lewis 1x1 supersonic tunnel. The inlet has rectan- Turbomachinery geometries will include endwall con- gular cross section, four external compression ramps touring and leaned, bowed, and swept blading. The located on the bottom, and contoured internal super- flow physics within these components will be sonic compression from the cowl at the top. Long extremely complex due to the presence of unsteady swept sideplates run from the leading edge of the rotor-stator interactions and large secondary flows. inlet to the cowl to prevent compressed flow from spilling over the sides of the inlet. A range of computational tools is envisioned for advanced turbomachinery design and analysis. The sub-scale model was recently tested to verify Figure 8 shows the relative levels of complexity of the computer results shown in Fig. 5. The calcula- these tools, ranging from the unaveraged Navier- tions were done on a X-MP supercomputer. The Stokes equations down to the quasi-one-dimensional calculations used a previously verified supersonic equations. Since the flow field within advanced PNS analysis [21 with nearly ten million grid points turbomachinery is highly three-dimensional and fun- and consumed 5 hours of CPU time. Figure 5 shows damentally unsteady, three-dimensional, unsteady, planes of color-coded pitot pressure contours in the viscous codes will be needed to predict the flow supersonic portion of the inlet. The near sideplate field. and cowl have been made transparent to allow easier veiwing of the computed results. The concentrated The major problem to be addressed in building and lines parallel to the ramps of the inlet indicate applying these codes is determining the appropriate shock locations while the concentration of blue level and type of temporal and spatial averaging. lines on the ramp and sidewall surfaces indicate The unaveraged, three-dimensional Navier-Stokes boundary layer distributions. The computed side- equations do not involve any averaging and are the wall boundary layer is thick and highly distorted by most complete and complex representation of the the sweeping action of the compression shocks, caus- unsteady flow field. The Reynolds-averaged, Navier- ing the flow to separate in the corner formed by the Stokes equations involve time-averaging of the tur- 1 cowl and sideplate just inside the cowl. A detailed bulent fluctuating components and require empirical picture of this last plane is shown in Fig. 6. On closure models for turbulence. These equations can the left side of the figure is color-coded Mach be further time-averaged to produce the steady, number and on the right is secondary velocity vec- time-averaged equations. Additional space-averag- tors. The high distortion produced by the vortex- ing can then be applied to produce average-passage like structure in the corner would cause serious equations, the axisymmetric equations, and, problems for the ramjet burners, while the corner finally, the quasi-one-dimensional equations. While separation might trigger an inlet unstart for this much less information is available from the quasi- design. The sub-scale model of Fig. 4 has encoun- one-dimensional equations, they can produce useful

2 information without a large expediture of computa- Data obtained at other instances in time during the tional resources if accurate empirical models are blade-passing cycle have been used to produce a carefully employed. The development of the empiri- motion picture which illustrates the ensemble- cal models and the verification of the code are averaged wake dynamics and its effect on the stator based upon a range of experimental measurements. flow field. This information is very valuable for developing closure models and verifying codes. Figure 9 shows the relative levels of complexity of experimental measurements as one attempts to obtain Chemical Reacting Flows more and more information in the time domain. Time- resolved measurements using hot-wire anemometry Future aerospace propulsion concepts involve the offer the most information about the unsteady flow combustion of liquid or gaseous fuels in a highly field. However, the challenges listed in Fig. 10 turbulent, internal air stream. Accurate computer usually make nonintrusiye, laser anemometry the codes to predict such chemical reacting flows will method of choice for obtaining high resolution data be a critical element in the design of these con- in turbomachines. It provides ensemble averaging cepts. Supercomputers will be needed due to the of random statistics while retaining and identifying large memory and long run-time requirements. the deterministic time dependency. In order to overcome the long measurement times required by Current research in chemical reacting flows at NASA laser anemometry and to capitalize on the detailed Lewis is divided into three major areas as shown in nature of the data captured, computer control of Fig. 13. The first area, Fluid Mechanics, involves data acquisition and real-time data reduction and the study of the basic fluid flow phenomena associ- display are required. NASA Lewis is recognized as ated with combustion without the added complexity of a world leader in the development and application heat release. Research in this area includes the of computer-controlled laser anemometry for turboma- development of computer codes for the multiphase chinery experimental research. Two examples of this processes of fuel sprays. The second area, Combus- research are discussed below. The first involves tion Chemistry, concentrates on the combustion of the calculation of rotor-stator interaction effects fuel and oxidizer without including the fluid in a turbine stage. The second involves the meas- mechanics. Research in this area includes the urement of kinetic energy distribution 'within a com- development of accurate combustion models for use pressor stator. in fluid mechanics codes. The third area, Turbu- lence-Combustion Interaction, deals with the inter- Turbine Rotor-Stator Interaction Calculation. A active effects of fluid mechanics and combustion Quasi-three-dimensional, viscous code for isolated chemistry. Research in this area includes the blade rows was modified to predict rotor-stator development of direct numerical simulation tech- interaction in a turbine stage [31. The geometry niques for the entire combustion process. was based upon the first stage of the Space Shuttle Main Engine (SSME) high-pressure fuel turbopump. A Two examples of current research in chemical react- converged, periodic solution was obtained after the ing flows are discussed below. The first involves stator had seen 10 pitch rotations of the rotor. experimental measurements in a planar reacting shear This solution required approximately 2.5 hr on a layer. The second involves results from a time- Cray X-MP supercomputer for a stator grid of 115 X accurate, two-dimensional shear layer code. 31 points and a rotor grid of 197 X 41 points. Mach contours from the solution are shown in Fig. 11 for Planar Reacting Shear Layer Experiment. The objec- one instant of time within a blade-passing period. tives of this experiment are to investigate the cou- The average stator inlet Mach number is 0.15. The pling between fluid mechanics and combustion in a wake region that develops downstream of the stator realistic environment and to provide benchmark data passes through the grid interface into the inlet for verification of computer codes. The test facil- portion of the rotor passage. Disturbances from the ity is shown in Fig. 14. The hydrogen-nitrogen passing rotor blades also affect the flow within stream mixes with the preheated air stream down- the upstream stator passage. This unsteady method stream of a plane splitter plate. Combustion occurs allows important physical effects to be captured where the fuel and air have properly mixed. Pres- that would not appear in a steady code. sure oscillations will exist due to the dynamic features of the flow; the coupling between these Compressor Turbulent Kinetic Enerqy Measurements. oscillations and the combusting shear layer will be Detailed measurements of the unsteady flow field examined. The unique features of this experiment within a compressor stator, operating downstream of include: continuous flow capability, high subsonic a transonic fan rotor, were obtained using laser velocities for both the hydrogen-nitrogen and air anemometry [41. Figure 12 shows the ensemble- streams, uncontaminated preheating of the air averaged, unresolved unsteadiness in the stator flow stream, and realistic high heat release. field for one relative rotor-stator position. The unresolved unsteadiness includes unsteadiness due Two-Dimensional Shear Layer Code. A time-accurate, to both turbulence and vortex shedding. Areas of two-dimensional, incompressible, fini te-difference high unresolved unsteadiness contain fluid in the code has been used to predict the unsteady develop- rotor blade wake. As the rotor blades rotate past ment of a forced shear layer [51. Figure 15 shows the stator blades, the rotor wakes are convected the vorticity structure for a Reynolds number of through the stator blade passages and, subse- 96 000, based on the forcing wavelength and the quently, chopped by the stator blades.

3 mean convective velocity. The positive and nega- The following paragraphs describe efforts at NASA tive vorticity contours originate at the boundary Lewis to develop and apply advanced computational layers specified at the inlet of the computational technologies to ICFM. domain. Forcing is applied at a long wavelength and smaller scale vortices spontaneously develop Local-Area Networks. In 1985, work kegan on the due to the natural instability of the shear layer. design of a local-area network (ERBNET) that would These small scale vortices cluster on the scale of allow ICFM researchers to access an: cmmunicate the longer forced wavelength. Small pockets of pos- between various terminals, computerr. and worksta- itive vorticity persist as remnants of the low- tions located in the Engine Researcr Suilding (ERB) speed boundary layer. The collective interaction complex. The network would also prcviie connectiv- of the small-scale vortices, as they merge into ity and high-speed data communicatic-s 3etween the larger scale structures, controls the dynamics of local computers, the NASA Lewis cenrrai mainframe the developing shear layer. These calculations computers, and remote computers such as the NAS. were performed on the NAS Cray-2 supercomputer. In designing the ERBNET system, special attention ADVANCED COMPUTATIONAL TECHNOLOGIES was given to system adaptability, flexibility, and growth potential. The decision was made to use Computer Capabilities and Requirements proven and available technology (Ethernet communica- tions and TCP/IP networking protocols) to reduce While the speed and memory capacity of computers cost, allow rapid implementation, and permit modular have increased dramatically over the past 40 years, upgrades. computer technology still remains a limiting factor in the quest to use high-fidelity computer simula- Figure 18 shows a block diagram representation of tions as tools in the propulsion system design the ERBNET configuration. A baseband Ethernet process. cable was installed in the ERE to provide high-speed (10 Mbitslsec) connections between the local comput- Given the current state of simulation models and ers. A utility band on the NASA Lewis-wide broad- computing capability, propulsion systems are being band cable (LINK) was used to interconnect ERBNET designed, for the most part, usfng simplified, with computers in the central Research Analysis Cen- highly empirical models. If one wanted to use a ter (RAC) and to provide user access to the NAS time-accurate, three-dimensional Navier-Stokes code facilities through the NASA Program Support Communi- to design a hypersonic inlet, it is estimated that cations Network (PSCN). it would take on the order of 100 hr of CPU time on a CRAY 2 supercomputer to obtain a single flow field Plans call for ERBNET to be expanded to provide solution. If a large number of repetitive runs are additional capabilities to a greater number of required (e.9. design optimization), the use of such users. For example, ERBNET will be tied ir;to off- a code would be impractical. One would need a speed site networks to allow sharing of resources and increase of 2 to 3 orders of magnitude (see Fig. 16) information with university and industrial research- to bring the CPU time down to a more reasonable 1 to ers. Additional equipment is continually being 2 hr. A similar shortfall exists in the simulation added to the network, including additional high- of complex three-dimensional flows in combustors, performance graphics . Work is under- compressors, turbines, and nozzles. way to develop graphics and scientific database software that will facilitate the interchange and When faced with the need for revolutionary, rather display of data across the breadth of ERBNET than evolutionary designs (as in the case of the devices. National Aerospace Plane), the empirical approach to propulsion system design would appear to be Artificial Intelligence. IFMD is currently investi- inadequate. Advances in computational technology gating the use of Artificial Intelligence (AI) con- and the abi 11ty to apply that technology are needed cepts as aids to researchers developing and using if we hope to satisfy the need for and fulfill the flow-solver codes. Such codes are typically written promise of computer-aided propulsion system design. by users with specific problems in mind and are con- sequently difficult for others to use and extend to Impact of New Technologies other problems. The effort at NASA Lewis attempts to capture the expertise gained by code developers Supercomputers are just one of many computer tech- in an "intelligent interface" that will allow oth- nologies that can make ICFM practical for propul- ers to make more effective use of the codes. sion system design. As shown in Fig. 17, the code development process can benefit from advances being The interface is initially being developed to sup- made in parallel processing, artificial intelligence/ port the PROTEUS code (a general-purpose three- expert systems, graphics, data communications, and dimensional Navier-Stokes flow solver being data base management. If used properly, these tech- developed at NASA Lewis using software engineering nologies can lead to a new way of conducting ICFM principles). The interface has been named PROTAIS research with analyses and experiments carried out to denote the introduction of AI techniques to the in a much more integrated and cooperative fashion. PROTEUS code. As shown in Fig. 19, the PROTAIS sys- The resulting databases, codes, and insights can tem provides help and advise for both expert and form the basis for a more confident, more aggres- novice users of PROTEUS. It features a constantly sive design methodology. growing knowledge base that reflects the experience and knowledge gained as the PROTEUS code is devel- oped and run under a variety of conditions.

4 Work, to date, has concentrated on developing the constructed 191. The Hypercluster will allow exper user facilities within PROTAIS. This consti- researchers to conveniently implement both share tutes the basic foundation of the interface, auto- memory and distributed memory architectures and 0 mating many of the tedious and time-consuming interactively study new algorithmic approaches. An asoects of setting up and running the code. The earlier version of the workstation is shown in PROTAIS code deveizoment is being done on a Symbol- Fig. 22. Assembly and testing of a 16-processor ics Workstation (ztn Fig. 20). At this writing, Hypercluster is expected to be com3'ited in late testing of the scf_iare design is being carried out 1988. Applications to be studied '-elude ICFM f ow in a stand-alone -cce (simulating the interface to solvers (analysis) and parallel prscessing of la er PROTEUS). In 19E. :ne ERBNET facilities will be anemometry data (experiments). used to connect t-? interface, installed on worksta- tions, to the PRGTEUS code that is running on an CONCLUDING REMARKS IBM 3033 mainframe. The, interface will then undergo testing and evaluation by the PROTEUS code Improvements in numerical algorithms, geometric developers. modeling, grid generation, and parameter modeling, as well as dramatic improvements in supercomputer Parallel Processinq. Advancements in solid-state processing speed and memory, are now making CFD a electronics and circuit design technology produced powerful tool for the aerodynamic design of propul- nearly linear increases in computer speeds from 1950 sion systems. Validation of existing and forthcom- to 1970. Since that time, computer manufacturers ing models and codes is needed to gain confidence have had to look toward new computer architectures in the use of the CFD codes as design tools. The (e.g., vector and parallel processors) t'o gain addi- code validation can best be accomplished by a close tional computing speed. The current generation of coupling of "benchmark" experiments, highlighting supercomputers makes use of multiple, bus-connected one or more basic flow mechanisms, and CFD code vector processors with shared memory to achieve development. Proper use of rapidly advancing compu- 100 Mflop-level speeds. Recently, Mulac, et al. tational technologies, including supercomputers, [61 have been successful in using four processors on parallel processors, graphics, artificial intelli- the CRAY X-MP/416 to calculate the flow field in a gence, and networks, can greatly enhance our capa- mu1 ti stage turbine. bilities to conduct this research. The Internal Fluid Mechanics Division of NASA Lewis is combining Aerospace researchers can expect this trend in the key elements of computational fluid dynamics, supercomputer technology to continue with the next aerothermodynamic experiments, and advanced computa- generation of systems employing 8 to 16 high-speed tional technology to bring internal computational processors to move closer to gigaflop performance fluid mechanics (ICFM) to a state of practical However, the high cost of supercomputers and the application for aerospace propulsion systems. need to share the available CPU time among many users (each wanting to run large, time-and-memory- REFERENCES consuming codes), often make supercomputers unavai able and/or impractical for many time-critical [11 Anderson, B.H.: Three-Dimensional Viscous applications, such as real-time simulation and Design Methodology for Advanced Technology Aircraft on-line data processing. Supersonic Inlet Systems, AIAA Paper 84-0194, January 1984. Recently, parallel architectures and state-of-the- art microDrocessors have been comblned to form a [21 Benson, T.J.: Three-Dimensional Viscous Calcu- new class of machine - the minisupercomputer. Mini- lation of Flow in a Mach 5.0 Hypersonic Inlet, AIAA supercomputers offer an attractive alternative to Paper 86-1461, 1986. mini-computers with some systems delivering near- supercomputer speeds (10 to 20 Mflop) and costing C33 Jorgenson, P.C.E., and Chima, R.V.: An Explicit less than $1M. A number of studies C7-811 are cur- Runge-Kutta Method for Unsteady Rotor/Stator Inter- rently underway to investigate the use of mini- action, AIAA Paper 88-0049, January 1988. supercomputers for solving ICFM algorithms. [41 Hathaway, M.D.: Unsteady Flows in a Single- At NASA Lewis, parallel computing will be used to Stage Transonic Axial-Flow Fan Stator Row, Ph. D mold a more synergistic ICFM research program. By Thesis, Iowa State Univ. NASA TM-88929, 1987. providing a parallel-processing "compute engine" for both analysts and experimentalists (see Fig. 21), we [51 Claus, R.W., Huang, P.G., and MacInnes, J.: hope to facilitate and accelerate progress in devel- Time-Accurate Simulations of a Shear Layer Forced at oping more powerful, validated codes. Experimental- a Single Frequency, AIAA Paper 88-0061, January 1988. ists will be able to use parallel processing to speed up the collection, manipulation, and viewing C61 Mulac, R.A., et a1 , "The Utilization of Paral- of data. The CFD codes, themselves, should become lel Processing in Solving the Inviscid Form of the commonly-used tools in planning, guiding, and inter- Average-Passage Equation System for Multistage preting results from experiments. Turbomachinery," In: Computational Fluid Dynamics Conference, 8th, Honolulu, Hawaii, June 9-11, 1987, NASA Lewis researchers are now working to determi ne pp. 70-80. the proper mix of algorithms and architectures for selected ICFM applications. To support this research, a reconfigurable, parallel processing workstation, called the "Hypercluster", is being

5 [71 Modiano, D.: Performance of a Common CFD LOOP [91 Blech, R.A.: The Hypercluster: A Parallel on Two Parallel Architectures, MIT CFD Laboratory Processing Test Bed Architecture for Computational Report CFDL-TR-87-11. November 1987. Mechanics Applications, NASA TM-89823. (Presented at the Summer Computer Simulation Conference, [81 Smith, W.A.: Multigrid Solution of Euler Montreal, Canada, July 27-30, 1987.) Equations, Ph. D Thesis, Cornel1 University 1987.

HIGHLY 3.0 FLOWS UNSTEADY FLOWS TURBULENCElTRANSlTlON SHEAR LAYERSIMIXING SHOCWBL INTERACTION MULTIPHASE FLOWS CHEMICAL KINETICS COMBUSTION \ /

RESEARCH THRUSTS

REACTING FLOWS

CD-87-29478 FIGURE 1. - RESEARCH THRUSTS IN INTERNAL COMPUTATIONAL FLUID MECHANICS.

EXPERIMENTATION

( MODELING OF PHYSICS VALIOATION OF COMPUTATIONS

UNDERSTANDING OF FLOW PHYSICS ACCURATE PREDICTIVE CODES CD-87-29477 FIGURE 2. - CLOSELY COUPLED EXPERIMENTAL AND COMPUTATIONAL RESEARCH.

6 ORIGINAL PAGE LUCK AND WHITE PHOTOGRAPH

FIGURE 3. - MACH 5 CRUISE AIRCRAFT.

FIGURE 4. - MACH 5 INLET EXPERIMENT.

7 ORIGINAL PAGE BLACK AND WHITE PHOTOGRAPH

FIGURE 5. - MACH 5 INLET ANALYSIS.

~URVEYSTATION

MACH NO. - 3.0

- 1.0

CD-86-19535

FIGURE 6. - MACH NUMBER AND SECONDARY VELOCITY VECTORS FOR MACH 5.0 HYPERSONIC INLET.

8 ORIGINAL PAGE BLACK AND WHITE PHOTOGRAPH

FIGURE 7. - GRAPHICS WORKSTATIONS FOR VISUALIZATION OF 3D FLOW FIELD DATA.

UNAVERAGED NAVIER cSTOKES

NEE0 FOR EMPIRICAL INFORMATION EQUATIONS

CD-07-20979 FIGURE 8. - LEVELS OF COMPLEXITY FOR COMPUTATIONAL ANALYSIS.

9 E- I .TIME DOMAIN ANTITAT WE IE-AVERAGED

INCREASING- AVERAGING OF VISUALIZATION TEMPORAL BEHAVIOR

CD-87-28980 FIGURE 9. - LEVELS OF COMPLEXITY FOR EXPERIMENTAL MEASUREMENTS.

ROTATING MACHINERY TRANSONIC VELOCITIES

RESTRICTED ACCESS

COMPUTER SD-87-28983 FIGURE 10. - TURBOMACHINERY LASER ANEMOMETRY SYSTEMS.

10 FIGURE 11. - ROTOR-STATOR INTERACTION CALCULATIONS FOR SSME FUEL TURBINE-MACH CONTOUR DISTRIBUTION.

FIGURE 12. - COMPRESSOR “TURBULENT” KINETIC ENERGY

ORtGlNAL PAGE BLACK AND WHITE PHOTOGRAPH

11 FLUID MECHANICS COMBUSTION CHEMISTRY

0 MULTIPHASE FLOW 0 CHEMICAL KINETICS COHERENT STRUCTURES DIFFUSION FLAMES, HIGHLY 3-0 FLOWS PREMIXED FLAMES 0 CATALYTIC COMBUSTION

LONG TERM GOAL: ACCURATE PREDICTIVE CODE WITH COUPLED FLUID MECHANICS AND CHEMISTRY FOR FUTURE AEROSPACE PROPULSION CD-87-20755 FIGURE 13. - ELEMENTS OF CHEMICAL REACTING FLOW RESEARCH.

FIGURE 14. - PLANAR REACTING SHEAR LAYER EXPERIMENTS.

FIGURE 15. - TURBULENT REACTING FLOW CALCULATIONS.

ORIGINAL PAGE 12 BLACK AND WHITE PHOTOGRAPH RAGED lo4 r

103 DS-AVERAGED Ti; 102 101 >. g E 100 I

10-1

10-2 10-3 10.2 10.1 100 101 102 103 104 105 106 COMPUTER SPEED, (mflops) CO-86-22063 FIGURE 16. - COMPUTER CAPABILITIES AND REQUIREMENTS FOR 3D HYPERSONIC INLET CALCULATIONS.

TECHNOLOGIES IMPROVED CODES SUPERCOMPUTERS MORE ACCURATE PARALLEL PROCESSORS EASIER TO USE EXPERT SYSTEMS VALIDATED BY EXPERIMENTS INTERACTIVE 3-0 GRAPHICS PROVIDE NEW PHYSICAL INSIGHTS NETWORKS BASIS FOR BETTER, FASTER DESIGNS OBMS FIGURE 17. - FUTURE IMPACT OF COMPUTERS ON INTERNAL COMPUTATIONAL FLUID MECHANICS.

TERMINALS PSCN

L.INK cn-8622054

FIGURE 18. - ERBNET LOCAL AREA COMPUTING NETWORK.

13 I a.

Y

3m

FIGURE 19. - ADVANCED INTELLIGENT WORKSTATIONS.

PROTEUS LeRC-DEVELOPED PROTAIS GENERAL-PURPOSE EXPERT INTELLIGENT INTERFACE NAVIER-STOKES FLOW SOLVER USER FRIENDLY INTERFACE DESIGNED FOR CFD APPLICATIONS HELP AN0 ADVICE FOR EXPERTS AND I NOVICES CONSTANTLY GROWING KNOWLEDGE OTHER NOVICE BASES (KB’S) CFD WILL EVOLVE WITH PROTEUS CODE CODES

FIGURE 20. - APPLICATION OF ARTIFICIAL INTELLIGENCE TO COMPUTATIONAL FLUID DYNAMICS.

14 CRAY X-MP ORlGINAC PAGE NAS BLACK AND WHITE PHOTOGRAPH

CFD DEVELOPMENT

:11 CLOSURE II VALIDATED PARALLEL COMPUTING CFD I METHODS I GUIDANCE ERBNET -11 11 -

EXPERIMENTS I FIGURE 21. - PARALLEL COMPUTING FOR VALIDATION OF CFD CODES.

-- I

8

FIGURE 22. - PARALLEL PROCESSING WORKSTATION

15 National Aeronautics and Report Documentation Page

1. Report No. 2. Government Accession No. 3. Recipient's Catalog No. NASA TM-100289

4. Title and Subtitle 5. Report Date January 1988 Internal Fluid Mechanics Research on Supercomputers for Aerospace Propulsion Systems 6. Performing Organization Code

7. Author@) 8. Performing Organization Report No. Brent A. Miller, *ernhard H. Anderson, and E-3937 John R. Szuch 10. Work Unit No. 1 505-62-21 9. Performing Organization Name and Address National Aeronautics and Space Administration 11. Contract or Grant No. Lewis Research Center

Cleveland, Ohio 44135-3191 13. Type of Report and Period Covered 12. Sponsoring Agency Name and Address Technical Memorandum

National Aeronautics and Space Administration 14. Sponsoring Agency Code Washington, D.C. 20546-0001

5. Supplementary Notes Prepared for the Third International Conference on Supercomputing - ICS'88, sponsored by the International Supercomputing Institute, Inc., Boston, Massachusetts, May 15-20, 1988.

6. Abstract The Internal Fluid Mechanics Division of the NASA Lewis Research Center is com- bining the key elements of computational fluid dynamics, aerothermodynamic exper- iments, and advanced computational technology to bring internal computational fluid mechanics (ICFM) to a state of practical application for aerospace propul- sion systems. The strategies used to achieve this goal are to (1) pursue an understanding of flow physics, surface heat transfer, and combustion via analy- sis and fundamental experiments, (2) incorporate improved understanding of these phenomena into verified three-dimensional CFD codes, and (3) utilize state-of- the-art computational technology to enhance the experimental and CFD research. This paper presents an overview of the ICFM program in high-speed propulsion, including work in inlets, turbomachinery, and chemical reacting flows. Ongoing efforts to integrate new computer technologies, such as parallel computing and artificial intelligence, into the high-speed aeropropulsion research are described.

17. Key Words (Suggested by Author@)) 18. Distribution Statement Aeropropulsion; Charge flow devices; Unclassified - Unlimited Simulation; Supercomputers; Flow Subject Category 34 phys i cs

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