<<

https://ntrs.nasa.gov/search.jsp?R=19720024135 2020-03-23T08:15:41+00:00Z

-2607

FLIGHT INVESTIGATION OF AN AJ3R-COOJLID PLUG|: WITH AN AFTERBURNING

: by Nick E. Samanich t •" ; : -li| -•. .-.^ Lewis Research Center Cleveland^ Ohio 44135

NATIONAL AERONAUTICS AND SPACE ADMINISTRATION • WASHINGTON, D. C. » SEPT?«pi ^ 1972 1. Report No. 2. Government Accession No. 3. Recipient's Catalog No. NASA TM X-2607 4. Title and Subtitle 5. Reportembet Date r 197„,..-,2„ FLIGHT INVESTIGATION OF AN AIR-COOLED PLUG NOZZLE WITH AN AFTERBURNING TURBOJET 6. Performing Organization Code

7. Author(s) 8. Performing Organization Report No. Nick E. Samanich E-6676 10. Work Unit No. 9. Performing Organization Name and Address 764-74 Lewis Research Center 11. Contract or Grant No. National Aeronautics and Space Administration

Cleveland, Ohio 44135 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

15. Supplementary Notes

16. Abstract A convectively cooled plug nozzle, using 4 percent of the air as the , was tested in 1967 K (3540 R) temperature exhaust gas. No significant differences in cooling character- istics existed between flight and static results. At flight speeds above Mach 1. 1, nozzle per- formance was improved by extending the outer shroud. Increasing engine power improved noz- zle efficiency considerably more at Mach 1. 2 than at 0.9. The effect of nozzle pressure ratio and secondary weight flow on nozzle performance are also presented.

17. Key Words (Suggested by Author(s)) 18. Distribution Statement system Flight test Unclassified - unlimited Plug nozzle Transonic Heat transfer

19. Security Classif. (of this report) 20. Security Classif. (of this page) 21. No. of Pages 22. Price* Unclassified Unclassified 55 $3.00

' For sale by the National Technical Information Service, Springfield, Virginia 22151 FLIGHT INVESTIGATION OF AN AIR-COOLED PLUG NOZZLE

WITH AN AFTERBURNING TURBOJET by Nick E. Samanich Lewis Research Center

SUMMARY.

A cooled plug nozzle was tested on an afterburning J85-GE-13 turbojet installed under the wing of an F-106B at Mach numbers from 0. 39 to 1. 3. The plug noz- zle, which utilized a parallel flow convective cooling scheme, was successfully cooled with 4 and 1. 8 percent of the engine primary air taken from the compressor discharge when subjected to exhaust gas temperatures as high as 1967 K (3540° R) and 1515 K (2727 R), respectively. No significant differences in cooling characteristics were ob- served during the flight tests compared with results obtained earlier in a static facility. The nozzle gross coefficient peaked at Mach 0. 945 for all the power settings tested. At this Mach number, the nozzle was in a high pressure field resulting from a terminal shock located just upstream of the nozzle assembly. The pressure rise behind the shock was amplified by the presence of the aircraft wing. The effect of varying the power setting on nozzle performance was significantly more pronounced at the higher Mach numbers. At comparable operating conditions, increasing power from military to maximum afterburning increased the nozzle gross thrust coefficient approximately 6. 5 counts at Mach 0. 9 and 16. 5 counts at Mach 1. 2. At flight speeds above Mach 1. 1 and with the engine in maximum afterburning, the nozzle gross thrust coefficient was increased when the outer shroud was extended from a retracted to an intermediate position. The effect of nozzle pressure ratio and secondary weight flow on nozzle performance is also presented.

INTRODUCTION

The plug nozzle has been of general interest for many years for use with advanced propulsion systems. It offers good aerodynamic performance, has a low infrared sig- nature, and can operate efficiently over a range of pressure ratios with minimal geometry changes (refs. 1 to 9). Because of concern regarding the feasibility associated with various cooling schemes, the use of plug to date has been limited to systems having low or moderate exhaust gas temperatures. Various plug cooling techniques have been under study for several years (refs. 10 to 15), they range from cooling the plug with engine to using air convectively, as a film, or a combination thereof. The perform- ance penalty associated with these cooling techniques becomes important if any compar- isons of nozzle types are to be made. If engine fuel is used, engine cycle efficiency is not affected, and the penalty is only one of system weight, complexity, and reliability. However, if engine is used, it becomes necessary to know the required quantity to adequately assess the performance penalty. In an attempt to establish plug nozzle cooling requirements, a full-scale air-cooled plug nozzle was designed, built, and tested with a -13 afterburning turbojet (ref. 10). It was demonstrated that a plug nozzle could be convectively cooled with about 3—percent of the primary engine airflow bled from the compressor discharge with average exhaust gas temperatures as high as 1860 K (3350° R). In order to establish whether external flow aggravates the nozzle cooling require- ments and to measure the installed nozzle performance, the "cooled plug" (ref. 10) was packaged in a flight nacelle and tested on a F-106B aircraft (refs. 16 and 17). The aft mounted under-wing nacelle (fig. 1) had a normal shock inlet and contained a J85-GE-13 turbojet. The 10° half-angle conical plug was tested at three power settings attaining maximum exhaust gas temperatures of 1967 K (3540° R). Several external shroud exten- sions were tested at maximum afterburning conditions. Test variables also included cor- rected secondary cooling flow from 1. 9 to 9. 7 percent of primary flow, exhaust nozzle pressure ratio from 2. 22 to 5. 8, and flight Mach number from 0. 39 to 1. 3. The results include the effect of engine power setting, shroud extension, secondary weight flow, and nozzle pressure ratio on the exhaust nozzle thrust characteristics. Properties of the plug coolant as well as external plug pressures and skin temperatures are also presented. ,

APPARATUS

Installation

Details of the airplane modifications and the nacelle-engine assembly are given in reference 17. A schematic of the research nacelle and plug nozzle is shown in figure 2. The nacelle was located at the 32 percent semispan with a downward incidence of 4-1>° (relative to the wing chord) so that the aft portion of the nacelle was tangent to the aft wing lower surface. The nacelle had 0 cant and was positioned to provide approximately 0. 64-centimeter (0. 25-in.) clearance at the wing trailing edge. Details of the wing mod- ifications, nacelle shape, and wide mounting strut used in these tests are given in refer- ence 18. The gas generator for the plug nozzle was a J85-GE-13 afterburning turbojet engine consisting of an eight-stage, axial-flow compressor directly coupled to a two-stage tur- bine, an annular , an , and a variable area primary exhaust noz- zle. The variable area nozzle was removed and replaced with a fixed plug body and tested with three fixed primary throat flaps. The plug nozzle was attached to the after- burner exit using a packing gland slip joint. The plug loads were taken out through three struts. Secondary cooling air was supplied from the inlet and metered at the periphery of the compressor face by a calibrated rotary valve. Several fuel control and mechanical changes were necessitated or made desirable due to the nonstandard mode of operation - afterburning with fixed primary throat areas. These changes included (1) Separate main engine and afterburner throttles (2) An auxiliary regulated pressure supply ("false PO") located in the aircraft wing, which was used to pressurize the afterburner fuel controller permissive port to allow afterburner fuel flow with part speed engine operation (3) A cockpit controlled valve, which permitted switching from "false ?„" pressure to engine compressor discharge pressure ?„ at the afterburner fuel controller (4) An automatic speed control capable of controlling engine speed from 85 to 99. 5 percent of rated. The following changes were incorporated as precautionary safety measures because of the increased risk of an engine overspeed resulting from an afterburner flame out with the fixed exit-area mode of operation. (1) The engine mechanical overspeed governor was readjusted with the flat occurring between 99. 6 and 100. 0 percent of rated engine speed. (Standard setting is ~106±1 per- cent of rated engine speed). (2) A fast response servo system designed to maintain engine speed by controlling the main engine throttle was incorporated. The set point was 100. 3 percent of rated speed. (3) An automatic engine shutdown system set to activate at 100. 5 percent of rated speed was also incorporated. In addition, critical afterburner liner and plug wall temperatures were wired to cockpit warning lights for pilot monitoring during the flight tests. Details of the pre- flight checkout are presented in appendix A. The aircraft cockpit duel throttle arrange- ment for the J-85 and the pilot panel display is shown in figure 3. Test Hardware

The basic plug (see fig. 4) was a 10° half-angle conic body that was attached to a 63. 5-centimeter (25.0-in.) nacelle by three equally spaced hollow support struts. The plug was 40. 70 centimeters (16.02 in.) at its maximum diameter and 141. 71 centimeters (55. 79 in.) long. The distance from the throat to the theoretical plug apex was 112.65 centimeters (44. 35 in.). Throat area variation was achieved with three fixed primary flaps that permitted engine operation at military, reheat B+ and maximum afterburning power. The flaps simulated hinged primary leaves and had boattail angles of 17.28°, 13.40°, and 7. 57°. Three outer shroud extensions were tested with the engine in max- imum afterburning power. They corresponded to a retracted position (x/l = -0.163) suit- able for low-pressure operation and two extended positions (x/l = 0.163 and 0. 343), which might be suitable for a typical flight acceleration profile. Only the retracted shroud was tested with the military and reheat B+ primaries.

Cool ing Details

The plug and strut cooling flow paths are shown in figure 5. Compressor discharge air was obtained from the four customer bleed ports located in the main frame section of the engine and ducted back through four lines to a torroidal distribution manifold. The cross section of the manifold was formed from 7. 62-centimeter (3. 0-in.) outside- diameter tubing. The final flattened oval shape had major and minor axes of 9. 80 centi- meters (3. 86 in.) and 3. 81 centimeters (1. 50 in.), respectively, with rounded ends hav- ing a radius of 1.91 centimeters (0. 75 in.). The mean diameter of the torus was 55. 88, centimeters (22.0 in.), and it fit in the annulus between the afterburner liner casing and the nacelle wall approximately 30.48 centimeters (12.0 in.) upstream of the plug nozzle. Three lines routed the plug and strut cooling air from the distribution manifold directly to the three plug support struts. After entering the struts, the coolant was forced toward the strut leading edge then channeled around the sides to the back and dumped into the plug cavity. The coolant then flowed forward through a Venturi passage where it im- pinged on the inside of the plug dome. It then entered the plug cooling channels, which were made of nickel fins brazed to the 0.157-centimeter (0. 062-in.) Inconel 625 outer wall. The fins were 0.794 centimeter (0. 313 in.) long, and the circumferential spacing was varied to yield approximately uniform plug wall temperatures at the maximum heat load condition. The coolant passed longitudinally aft and was discharged out of an an- nulus located at an axial station corresponding to 60 percent of a full length plug. The remaining plug tip was film cooled by the discharged gases. The flow area of the plug exit annular coolant passage during hot operation was calculated to be 28.0 square centi- o meters (4. 34 in. ).

4 The primary flap was film cooled with residual cooling air from the afterburner liner at all power settings; however, this was supplemented when operating in maximum afterburn with film from two additional cooling slots. The two slots, fed by six lines from the distribution manifold, were located immediately upstream and downstream of the plug support struts. In addition, secondary air and (with the retracted shroud) exter- nal flow was somewhat effective in convectively cooling the outer side of the primary flap. All cooling-air lines feeding the plug assembly had provisions for the installation of orifices immediately downstream of the distribution manifold. For the tests with mil- itary engine power, all nine lines were fitted with solid blanks preventing any cooling-air flow. For reheat B+ engine operation, the six lines feeding the film cooling manifolds were blanked and 1. 21 centimeter (0. 475 in.) diameter orifices were used in the three lines supplying strut and plug cooling air. The three lines to the struts were left open (no orifices) and 0. 823-centimeter (0. 324-in.) diameter orifices were used in the other six lines for tests in maximum afterburning. The orifices were sized during static test- ing in an altitude facility to minimize cooling flow rates at the various power settings.

Instrumentation

Although the plug nozzle had extensive instrumentation built into the hardware (ref. 10), only a selected number of thermocouples were used during the flight tests. The coordinate system used to locate the instrumentation is shown in figure 6 and a com- plete tabulation of the pressure and temperature measurement locations on the plug is made in table I. In addition to a skin temperature measurement, the three flaps tested had 12 area weighted pressure taps located as shown in figure 7. Also shown in the sec- ondary flow instrumentation, four total-pressure and temperature probes attached to the outer shrouds with the survey plane near the secondary flow exit. Compressor bleed air was used for plug cooling when afterburning. During static check out of the plug assem- bly total and static pressures were used in the four calibrated compressor discharge lines to measure total coolant flow. Similar instrumentation was used in the three lines supplying coolant to the struts and plug. During the flight testing, the quantity of plug coolant flow was calculated in a similar manner but primary flap film coolant was esti- mated as being the same constant percentage of plug coolant as that measured in the static testing. Compressor discharge pressure P« was also monitored at one of the customer air attachment ports. The inlet, secondary air valve, and compressor face instrumentation are shown in figure 8. Additional engine instrumentation included fuel flowmeters, an engine speed sensor, and pressure and temperature surveys at the turbine discharge (ref. 16). A flight calibrated test boom located on the aircraft nose was used to determine free- stream static and total pressures and aircraft angle-of-attack and sideslip angle. Photographs of some of the plug nozzle components are shown in figures 9 to 14. The five assemblies flight tested are shown installed on the F-106B aircraft in figure 15.

PROCEDURE

All flights were made out of Selfridge Air Force Base in Mt. Clemans, Michigan, with a test corridor over Lake Huron used during data acquisition. A total of eight flights were made during this test series. A prescribed flight trajectory was followed, which resulted in a repeatable angle-of-attack and eleven-deflection schedule (see fig. 16). For the data taken at a nominal 0.4 Mach number, the aircraft was at a pres- sure altitude h of 228. 6 meters (750 ft), an angle-of-attack a of 6. 5°, and had a nom- inal elevon deflection 5 of 3 on the wing above the plug nozzle. For the afterburning configurations, a predetermined operating procedure was fol- lowed (see appendix A). The procedure established was based on being operationally safe and one that minimized fuel consumption prior to data acquisition. The "false P^" pressure used to activate one of the afterburner fuel permissives was set prior to flight to a value that would provide fuel flow conditions adequate for an afterburner light and would also match conditions during the transition to engine PQ. c c. J The predetermined gage values were 3.0338x10 and 3. 1717x10 newtons per square meter (44 and 46 psi) for the reheat B+ and maximum afterburner primaries, respec- tively. The J-85 main burner was lit shortly after takeoff. Afterburner ignition was made at an engine speed of 75 percent NR, Mach number Mn of 0.5, and an altitude of + 4572 meters (15 000 ft) for the reheat B primary and 80 percent NR, 0.4 Mach, and 3048-meter (10 000-ft) altitude for the maximum afterburning primary. Attempts to + light-off at the predetermined 80 percent NR were unsuccessful with the reheat B pri- mary. It was speculated that the colder in-flight compressor face air temperature

T2 = 258 K (465° R), compared with that during the static ignition limit tests (appen- dix A), was the cause. After successful light-off, engine speed was advanced using both throttles and keeping turbine discharge temperature in the "safe" T^ corridor. Upon reaching 95 percent of rated speed, the transition to engine P, and engine speed control was made. The aircraft was then accelerated, and the altitude changed corresponding to conditions desired for data acquisition. Just before data acquisition, the engine speed was increased to rated and the afterburner throttle advanced until rated T5 temperature was reached. These conditions correspond to rated afterburner power at the nozzle throat area being tested. With some of the configurations tested, data were taken at var- ious Tr temperatures and secondary cooling flows. DATA REDUCTION

Engine airflow was determined using prior engine calibration data (ref. 19) along with in-flight measurements of engine speed, pressure, and temperature at the com- pressor face. Total temperature TO, total pressure Pg, and effective area Ago were obtained by using the values of engine airflow, engine and afterburner fuel flows, the total pressure and temperature at the turbine discharge, along with afterburner temper- ature rise and pressure drop calibration results. Calibrations of the secondary-f low - valve pressure drop and position were used to determine secondary airflow. Compres- sor bleed air, used for plug cooling in the afterburning configurations, was determined from line orifice pressure drops and previous flow calibrations. The quantity of bleed air used for supplemental film cooling of the primary flaps when in maximum afterburn was included in the primary weight flow Wp. Prior in-flight thrust system calibrations were made with reference cylindrical ejec- tors. The ejector thrust characteristics in conjunction with the load-cell readings were used to determine a nacelle tare force. The tare force, consisting of the inlet momentum and all external forces on the nacelle forward of the nozzle attachment flange (nacelle station 457. 2 cm (180 in.)), was shown to be a function of flight speed and inlet spillage. Knowing these two parameters during the research flights enabled the tare to be deter- mined. The load-cell measurement was used in combination with the tare force to deter- mine nozzle gross thrust minus drag. Details of the calibrations and of the thrust- measuring system for the F-106 are presented in reference 16. The basic nozzle performance parameter selected was a ratio of measured gross thrust minus drag ratioed to the ideal thrust of the primary flow. The ideal thrust of the primary was calculated from the known mass-flow rate expanded isentropically from its total pressure to ambient pressure pfl. Pressures were integrated over the surfaces of the primary flaps and the calculated axial forces are presented in terms of percent of ideal primary thrust. The axial thrust of the primary, secondary, and plug coolant streams in their respective exit planes was also calculated. Total pressures, temper- atures, and weight flows were used with known exit areas to obtain the thrust contribu- tions. The primary and plug coolant forces were adjusted for an assumed 10° flow angu- larity in their exit planes. Individual pressure distributions along the plug body are also presented. RESULTS AND DISCUSSION

Performance Characteristics

Three primary throat areas were tested. When operating at rated turbine discharge temperature TV the three exit areas corresponded to nominal J85 power settings of mil- itary, reheat B+, and maximum afterburning. The effect on the nozzle gross thrust coef- ficient (F - D)/F. is shown in figure 17. The data at military and reheat B+ power set- tings were taken wit" h approximately 3. 2 percent corrected secondary airflow (JJ\]Tr, while the data at maximum afterburning was taken with approximately 6. 5 percent. The shaded area in figure 17, below the afterburning configuration data, represents the momentum of the plug coolant calculated using properties at its discharge plane (Sta 608. 2 cm (239.45 in.)). At all three power settings, the peak nozzle gross thrust coefficient oc- curred at Mach 0. 945 followed by a sharp drop at Mach 0. 98. At Mach 0. 945, a terminal shock was located just upstream of the nozzle assembly. As described in reference 20, the combination of the flow field of the wing and the flow field around the nacelle, which was reflected by the lower surface of the wing, amplified the recompression of the flow through the shock and over the nozzle assembly. These higher pressures reduced the nozzle drag and increased the nozzle performance. A sharp drop in pressure and per- formance accompanies the terminal shock movement off the nozzle assembly, which oc- curred at Mach 0.98. An attempt was made to compare the nozzle thrust coefficient at comparable operating conditions in terms of Mach number, nozzle pressure ratio, and plug coolant flows. The performance was adjusted to correspond to that expected with 6. 5 percent corrected secondary weight flow W\T, no plug coolant flow thrust, and a nozzle pressure ratio Pg/^O of 3" ^5 and 4- 5^ at Mach 0. 9 and 1. 20, respectively. The adjustment in performance was based on a calculated exit momentum of the plug coolant and characteristic variations in performance with secondary coolant flow and nozzle pres- sure ratio measured in these tests and data reported in reference 9. The data and incre- mental corrections are tabulated in table n and the final adjusted performance shown as a function of nacelle to primary throat area ratio in figure 18. The data indicate a linear increase in thrust coefficient with increasing throat area. The gross thrust coefficient increased 6. 5 and 16. 5 counts at Mach 0. 90 and 1.2, respectively when the area ratio

(An/AEg) was decreased from 4. 34 to 2. 87 (military to maximum afterburner power). Three external shroud extensions were tested with the engine in maximum afterburn- ing: A fully retracted position suitable for low pressure ratio operation (x/l = -0. 163) and two extended positions (x/l = 0. 163 and 0. 343). The most extended shroud corre- sponds to one that would be required for optimum performance when operating at typical supersonic cruise pressure ratios. As can be seen in figure 19, there was a slight im- provement in performance at flight speeds above Mach 1. 1 when the outer shroud was ex- tended from a retracted (x/l = -0. 163) to an intermediate position (x/l = 0. 163). The data from cold flow tests on a similar isolated configuration (ref. 5) indicated that shroud translation was not beneficial until a Mach number of approximately 1. 50 had been reached, when operating at the same nozzle pressure ratios as in the present investigation. The effect of secondary weight flow variations on nozzle thrust coefficient is shown in figure 20. The data are presented for the military and reheat B+ power settings at nominal Mach numbers of 0. 9 and 1. 2. In general, increasing secondary weight flow 1 percent of the primary flow resulted in a corresponding percent increase in thrust coefficient. The effect of exhaust nozzle pressure ratio on the nozzle thrust coefficient at Mach 0. 9 is shown in figure 21. The limited data obtained at the military and reheat B+ throat settings indicates similar characteristic trends. The upper values of pressure ratio were limited by attaining rated turbine outlet temperature TS at 100 percent rated me- chanical speed for the J85 engine. At Mach 0. 9 and a reheat B+ power setting increasing exhaust nozzle pressure ratio from 3. 25 to 3. 75 increased the nozzle gross thrust coeffi- cient about 3. 5 counts. The engine and coolant flow conditions for all the rated engine points used in the per- formance evaluation are presented in figure 22 for the military, reheat B+, and maximum afterburning power. Except for a few incorrect secondary valve settings, the variation in secondary cooling flow over the Mach number range for the military and reheat B+ power settings is a result of estimating the pumping characteristics prior to the flight tests. The secondary valve was set at full open for the tests with the maximum after- burning primary. The variation in exhaust gas temperature Tg with all the power set- tings was primarily due to the inability to set exact engine conditions with the dual throt- tle control system and the normal variation due to changes in compressor efficiency with Reynold's number. The integrated pressure measurements on the primary flaps along with calculated primary, secondary, and plug coolant exit momenta are presented over the Mach number range in figure 23(a) and (b) for the military and reheat B+ power settings, respectively, and in figures 23(c) to (e) for the maximum afterburning configurations. For all config- urations with the retracted outer shroud (figs. 23(a) to (c)), the primary flap drag is minimal at Mach 0. 945, when the terminal shock is located just ahead of the nozzle as- sembly and then increases to its peak value at Mach 0. 98 when the terminal shock passes off the assembly. With the extended outer shrouds, the primary flap is shielded from ex- ternal flow effects, and the location of the terminal shock no longer influences the flap drag values. As indicated previously, increases in adjusted nozzle thrust coefficient of 6. 5 and 16. 5 counts were measured at Mach 0. 9 and 1. 2, respectively, when increasing the power setting from military to maximum afterburning (see fig. 18). From the com- ponent force data (fig. 23) and the data showing the effect of secondary weight flow (fig. 20), it can be seen that approximately one quarter of the performance increase was due to a reduction in primary flap drag and another one quarter resulted from higher secondary flow momentum. The remaining increase should, therefore, be due to pres- sure forces on the plug body. Although the measured plug pressures showed an in- crease, no attempt was made to resolve them into a component force. Pumping characteristics at Mach 0. 9 and 1. 2 for the military and reheat B+ config- urations are presented in figure 24. Secondary to primary pressure ratio is shown as a function of corrected secondary weight flow in figures 24(a) and (b). Figure 24(c) shows the effect of nozzle pressure ratio on secondary to primary pressure ratio at Mach 0. 9 and at a nominal corrected secondary weight flow ratio (jf\T of 0. 033. In making any direct comparisons of secondary pressure ratios required to pump comparable corrected secondary weight flows with the different configurations, the reader is reminded that the nozzle pressure ratios Pg/Pn were not identical and do affect the absolute magnitudes. With the retracted shroud configurations, the secondary pumping is achieved primarily by. the external stream rather than the primary jet. However, varying the configuration from the military to maximum afterburning did influence the pumping pressure require- ments (fig. 24(d)). It is believed that this effect came about by a change in back pres- sure at the secondary exit as evidenced by pressure instrumentation on the external side of the primary flap. Primary flap pressures increased when power was increased from military to maximum afterburning probably due to a combination of lowering the primary flap boattail angle /3 and increasing the exhaust plume diameter because of the larger exit diameter and higher exhaust gas temperatures. An attempt was made to compare the pumping characteristics at the three (retracted shroud) power settings tested at Mach 0. 9 at a corrected secondary weight flow U>\T of 0. 063. The maximum afterburning thrust coefficient data (fig. 22(c)) and the reheat B+ data (fig. 24(b)) were adjusted to cor- respond to a nozzle pressure ratio Pg/Pn of 3- 5- Tne sensitivity of the reheat B+ con- figuration to nozzle pressure ratio (fig. 24(c)) was assumed for both reheat settings. The results indicate an increasing secondary pressure ratio requirement (Pg/Pg = 0. 30, 0. 324, and 0. 35) as power is increased from military to reheat B+, to maximum after- burning, respectively, to maintain 0.063 corrected secondary flow at a nozzle pressure ratio of 3. 5 and a flight Mach number of 0.9.

Cooling Characteristics

The plug wall and coolant temperature variations, which were obtained statically (ref. 10) and in flight, are compared in figure 25 for the maximum afterburning config- uration. An attempt was made to compare data points taken at comparable operating con- ditions. The quantity of plug coolant was slightly different in maximum afterburning

10 (about 4 percent in the flight tests compared to 3— percent of the total weight flow during the static tests). As can be seen, no significant differences appear to exist. The some- what higher wall temperatures obtained in flight do fall within the data scatter from the ground test and do not indicate any significant temperature changes. Plug wall temperatures at the throat are presented as a function of exhaust gas tem- perature and compared with data obtained statically in figure 26. The data indicate an approximately linear increase in wall temperature with increasing exhaust gas temper- ature with less coolant margin existing with the reheat B+ power setting. A comparison of the wall temperature variation at the throat (on the primary flap and plug wall) with exhaust gas temperature To at Mach 0. 9 is shown in figure 27. At a reheat B+ power setting, the primary flap temperature increased at a faster rate than the plug wall and was approximately 78 K (140° R) hotter at rated conditions. Secondary weight flow did not appear to have a measurable effect on the primary flap skin temperature in the reheat B+ power setting (fig. 28). The data shown are at Mach 0. 9 and over a range of corrected secondary weight flows from 0. 019 to 0. 069. The plug coolant flow path and measuring stations are shown schematically in fig- ure 29. Coolant pressure and temperature variations along with corresponding metal temperatures are shown at discrete Mach numbers for the afterburning configurations in figure 30. The data are presented for the reheat B+ and the maximum afterburn primary with retracted, intermediate, and extended shroud in figures 30(a) to (d), respectively. The hottest skin temperatures were measured during the low speed flights (M^ ~ 0.4) and occurred at a station approximately midway between the throat and coolant discharge plane. At Mach numbers greater than 1.0, the hottest metal temperatures occurred near the throat plane. Corresponding pressure distributions along the external plug surface are presented in figure 31 (a) to (d). In addition, the plug pressure variation in military power is presented in figure 31(e). With all the configurations tested, a sharp over expansion occurred immediately aft of the throat followed by a recompression and sub- sequent pressure oscillations diminishing in intensity. Local pressures immediately downstream of the throat approaching 25 percent of ambient pressure p~ were recorded at Mach numbers near 1. 0.

SUMMARY OF RESULTS

An air-cooled plug nozzle was tested installed under the wing of an F-106B aircraft at Mach numbers from 0. 39 to 1. 3. Power setting was varied from military to max- imum afterburning, and the cooling characteristics compared with data previously ob- tained in an altitude cell. The effect of power setting, shroud extension, secondary cool- ing flow and nozzle pressure ratio on the exhaust nozzle thrust characteristics are pre- sented. The following results were obtained: 11 1. No significant differences in cooling characteristics were observed during the flight tests compared with previous static results. 2. The plug nozzle was adequately cooled using approximately 1. 8 and 4. 0 percent compressor bleed air with exhaust gas temperatures of 1515 and 1967 K (2727° and 3540° R), respectively. 3. At comparable operating conditions, increasing power setting from military to maximum afterburning increased the nozzle thrust coefficient approximately 6. 5 counts at Mach 0.9 and 16. 5 counts at Mach 1.2. 4. At Mach numbers above 1. 1 and at maximum afterburn power, a slight perform- ance advantage was indicated by extending the outer shroud from a retracted to an inter - mediate position. 5. A 1-percent increase in corrected secondary weight flow increased nozzle gross thrust coefficient about 1 percent. 6. At Mach 0. 9 and a reheat B+ power setting increasing exhaust nozzle pressure ratio from 3. 25 to 3. 75 increased the nozzle gross coefficient approximately 3— counts.

^ Lewis Research Center, National Aeronautics and Space Administration, Cleveland, Ohio, March 20, 1972, 764-74.

12 APPEND IX A

PREFLIGHT CHECK-OUT

All of the engine control changes and other modifications were made on a calibrated night engine (SN244-028) (ref. 19), which was installed in a mock flight nacelle and checked out operationally in an altitude cell. The test program included (a) Defining the starting envelope and starting sequence for all nozzle exit areas to be flight tested (b) Sizing appropriate orifices for proper plug coolant flow distribution for the after - burning configurations (c) Evaluating the adequacy and reliability of the new engine control system (d) Defining safe operational limits of all critical parameters (e) Test pilot familiarization and operational experience with the new throttle system. Interest in the afterburner light-off envelope stemmed from the desire to minimize fuel consumption prior to data acquisition and to obtain safe, smooth, and repeatable lights. The afterburner ignition data obtained are shown in figure 32. All the data pre- sented were obtained with the engine speed at about 80 percent of rated and with an air temperature of about 294 K (530° R) at the compressor inlet. From the data, it was con- cluded that light-off at 80 percent rated engine speed, Mach 0.4, 3048-meter (10 000-ft) altitude and Mach 0. 5, 4572-meter (15 000-ft) altitude with the maximum afterburn and reheat B+ primaries, respectively, would be satisfactory for the flight tests. The plug body was designed to withstand maximum skin temperatures of 1222 K (2200 R). The orifice sizing for coolant flow distribution was chosen to allow for some temperature margin for the flight tests. The following orifice sizing was arrived at:

Engine Orifice diameter power To plug (three lines) To primary flap (six lines)

Maximum Open line 0. 823 cm (0. 324 in. ) diam afterburn (no orifice plate) Reheat B+ 1.21cm (0.475 in. ) diam Closed line (blank orifice plate) Military Closed line Closed line (blank orifice plate) (blank orifice plate)

13 The control system checkout was predominantly addressed to defining the dynamic characteristics of the system and its response to an afterburner flame-out. Attempts to simulate a flame-out were made by dropping out the afterburner fuel flow permissive sig- nal which initiated the closing of a fast acting fuel valve. The resulting transient with all control equipment functioning is shown in figure 33. The response of the engine to a ±34 kilonewtons per square meter (±5 psi) pressure differential existing during a transi- tion from "false Pg" to engine P3 was also examined. No adverse effects were noted. With the dual throttle control system, it was possible to overheat the nozzle assem- bly or increase turbine inlet temperature beyond acceptable limits during the transition to rated conditions. In order to minimize the possibility of this happening, a safe oper- ating corridor was empirically established using visual monitoring of the flame intensity in the afterburner with the use of an aft mounted periscope, and the lean blowout limits of the afterburner. This corridor was defined in terms of engine speed and turbine dis- charge temperature T5 and is presented

Rated speed, Turbine discharge temperature NR> T5 percent K±25 °R±45

80 673 1211 85 698 1256 90 728 1310 95 783 1409 98 813 1463 100 838 1508

In addition, critically located thermocouples were selected for in-flight cockpit monitoring. After completion of the static checkout, the entire engine assembly was installed in a flight nacelle and mounted to the aircraft. Several ground run-ups in partial afterburn- ing power were made on the aircraft before initiation of the flight program.

14 APPENDIX B

SYMBOLS

A area, cm 2 (in. 2) 2 2 AE8 nozzle effective throat area (hot), cm (in. ) D drag, N (Ibf) d diameter, cm (in.) F nozzle gross thrust, N (Ibf) (F-D)/F. nozzle gross thrust coefficient f component force, N (Ibf) H perpendicular distance from plug surface, cm (in.) h altitude, m (ft) L total distance along plug surface from plug front end to coolant exit plane, cm (in.) I plug length measured from theoretical throat with military flap to theoret- ical plug apex, 112. 65 cm (44. 35 in.) M Mach number

NR rated engine rotor speed 2 P total pressure, N/m abs (psia) 2 p static pressure, N/m abs (psia) T total temperature, K (°R) w weight flow, kg/sec (Ibm/sec) x theoretical throat station on plug surface with military primary, station 537. 69 cm (211. 69 in.) y distance along plug surface from plug front end a angle of attack, deg /3 primary flap boattail angle, deg 6 eleven deflection, deg ?7 maximum distance from plug surface to primary nozzle 0 angle, deg

15 A total distance around strut surface £ distance along strut surface from reference station T secondary flow to primary flow total temperature ratio co ratio of secondary to primary weight flow u> c ratio of total compressor bleed (plug coolant plus primary film) to primary weight flow co ratio of plug coolant to primary weight flow corrected secondary weight flow ratio Subscripts: c coolant 1 ideal n nacelle reference dimension, 63. 5 cm (25. 0 in. ) p primary gas at throat (station 8) R rated conditions S secondary exit, sta 516. 26 cm (203. 25 in. ) W wall 0 free stream 2 compressor inlet station 3 compressor discharge station 8 primary nozzle throat station

16 REFERENCES

1. Schmeer, James W. ; Kirkham, Frank S.; and Salters, Leland B. , Jr.: Performance Characteristics of a 10° Conical Plug Nozzle at Mach Numbers Up to 1.29. NASA TM X-913, 1964. 2. Herd, J. R. ; Golesworthy, G. T. ; and Herbert, M. V. : The Performance of a Centrebody with a Parallel Shroud in External Flow, Part I. Rep. ARC-CP-841, Aeronautical Research Council, Gt. Britain, 1966. 3. Herbert, M. V.; Golesworthy, G. T.; and Herd, R. J. : The Performance of a Centrebody Propelling Nozzle with a Parallel Shroud in External Flow, Part n. Rep. ARC-CP-894, Aeronautical Research Council, 1966. 4. Bresnahan, Donald L.; and Johns, Albert L. : Cold Flow Investigation of a Low Angle Turbojet Plug Nozzle with Fixed Throat and Translating Shroud at Mach Numbers From 0 to 2. 0. NASA TM X-1619, 1968. 5. Bresnahan, Donald L. : Experimental Investigation of a 10° Conical Turbojet Plug Nozzle with Iris Primary and Translating Shroud at Mach Numbers From 0 to 2. 0. NASATM X-1709, 1968. 6. Bresnahan, Donald L. : Experimental Investigation of a 10° Conical Turbojet Plug Nozzle with Translating Primary and Secondary Shrouds at Mach Numbers From 0 to 2. 0. NASA TM X-1777, 1969. 7. Harrington, Douglas E. : Performance of a 10° Conical Plug Nozzle with Various Primary Flap and Nacelle Configurations at Mach Numbers From 0 to 1. 97. NASA TM X-2086, 1970. 8. Huntley, Sidney C. ; and Samanich, Nick E.: Performance of a 10° Conical Plug Nozzle Using a Turbojet Gas Generator. NASA TM X-52570, 1969. 9. Samanich, Nick E. ; and Chanberlin, Roger: Flight Investigation of Installation Effects on a Plug Nozzle Installed on an Underwing Nacelle. NASA TM X-2295, 1971. 10. Clark, John S. ; Graber, Edwin J. ; and Straight, David M.: Experimental Heat Transfer and Flow Results From an Air-Cooled Plug Nozzle System. NASA TM X-52897, 1970. 11. Chenoweth, Francis C.; and Lieberman, Arthur: Experimental Investigation of the Heat Transfer Characteristics of a Film-Cooled Plug Nozzle with Translating Shroud. NASATND-6160, 1971.

17 12. Behiem, Milton A. ; Anderson, Bernhard H. ; Clark, John S. ; Corson, Blake W. , Jr.; Stitt, Leonard E. ; and Wilcox, Fred A. : Supersonic Exhaust Nozzles. Aircraft Propulsion. NASA SP-259, 1971, pp. 233-282. 13. Stepka, Francis S. ; and Chambellan, Rene E. : Feasibility Study of Jet-Fuel-Cooled Plug Nozzle for Afterburning Turbojet. NASA TM X-2304, 1971. 14. Jeracki, Robert J. ; and Chenoweth, Francis C. : Coolant Flow Effects on the Per- formance of a Conical Plug Nozzle at Mach Numbers From 0 to 2.0. NASA TM X-2076, 1970. 15. Clark, John S. ; and Lieberman, Arthur: Thermal Design Study of an Air-Cooled Plug-Nozzle System for a Super sonic-Cruise Aircraft. NASA TM X-2475, 1971. 16. Groth, Harold W. ; Samanich, Nick E. ; and Blumenthal, Philip Z. : Inflight Thrust Measuring System for Underwing Nacelles Installed on a Modified F-106 Aircraft. NASA TM X-2356, 1971. 17. Crabs, Clifford C. ; Mikkelson, Daniel C. ; and Boyer, Earle O. : An Inflight Investigation of Airframe Effects on Propulsion System Performance at Transonic Speeds. Presented at the 13 Annual Symposium of the Society of Experimental Test Pilots, Los Angeles, Calif., Sept. 25-27, 1969. 18. Mikkelson, Daniel C. ; and Head, Verlon L. : Flight Investigation of Airframe Installation Effects on a Variable Flap Ejector Nozzle of an Underwing Engine Nacelle at Mach Numbers From 0. 5 to 1. 3. NASA TM X-2010, 1970. 19. Antl, Robert J. ; and Burley, Richard R.: Steady-State Airflow and Afterburning Performance Characteristics of Four J85-GE-13 Turbojet . NASA TM X-1742, 1969. 20. Wilcox, Fred A. ; Samanich, Nick E. ; and Blaha, Bernard J. : Flight and Wind Tunnel Investigation of Installation Effects on Supersonic Cruise Exhaust Nozzles at Transonic Speeds. Paper 69-427, AIAA, June 1969.

18 TABLE I. . PLUG INSTRUMENTATION

[See fig. 6. ]

Instrument Dimensionless Angle, Instrument Dimensionless Angle, Dimensionless number distance along e, number distance along e, perpendicular plug surface, deg plug surface, deg distance from y/L y/L plug surface, H/D

Plug static pressures (hot gas side) Plug wall temperatures

PHPL-1 0 0 TWPL-2 0.0341 10 PHPL-2 .1041 357.5 TWPL-3 .0536 5 PHPL-3 .2939 0 TWPL-28 .6545 60 PHPL-4 .3627 0 TWPL-3 1 .9909 63.5 PHPL-5 .3741 14 TWPL-33 .2995 120.0 PHPL-6 .3950 30 TWPL-36 .2995 240.0 PHPL-7 .4273 45 TWPL-41 .3684 105.0 PHPL-8 .4659 60 TWPL-43 .3684 150.0 PHPL-9 .5218 75 TXPL-10 'l.303 60.0 PHPL-10 .6545 90 PHPL-11 .7491 105 Plug coolant temperatures PHPL-12 .8705 120 TCPL-1 (d) 15.0 PHPL-13 .9909 131 TCPL-11 (d) 75.0 PHPL-14 .1041 315 TCPL-21 0.3627 18.5 PHPL-15 .1352 300 TCPL-22 .3627 48.5 PHPL-16 .2405 300 TCPL-31 .9909 20.0 PHPL-17 .2939 270 TCPL-32 .9909 50.0 PHPL-18 .3627 255 TCPS-9 (fl 120 PHPL-19 .3741 239 TCPS-10 (f) 240 PHPL-20 .3950 225 PHPL-21 .4273 210 Primary flap metal temperature PHPL-22 .4659 195 TWPS-13 PHPL-23 .5218 180 (i) 120.0 PHPL-24 a 0 1.092 Primary flap film temperatures PHPL-25 bl. 183 0 C PHPL-26 1.341 TCPS-3 (g) 0 PHPL-27 .2386 358.3 TCPS-5 (h) 0

Coolant static ^pressures Strut wall temperatures 5/A PCPL-1 0.0511 15 PCPL-8 .9909 10 TWST-1 0 0 0. 1376 PCPL-16 .9909 70 TWST-10 1.00 .4576 PCPL-17 (d) 45 TWST-13 .4636 .7376 PCPL-18 (e) 180 TWST-15 1.00 .7376 PCPL-19 (e) 5 PCPL-21 .3627 56.5 PCPS-1 W 0 PCPS-2 (0 120 PCPS-3 (D 240 PCPS-4 (g) 58 PCPS-8 (h) 58

Coolant total pressures

HCPL-1 0.9909 5 HCPL-2 22.5 HCPL-4 65 HCPL-9 187.5 HCPL-10 232.5 HCPL-11 277.5 HCPL-12 322 .,5 aFilm cooled extension, 10.16 cm (4.0 in.) downstream of film exit. bFilm cooled extension, 20. 32 cm (8. 0 in.) downstream of film exit. GPlug apex. Impingement pipe; y/L = 0.0705; r = 2.54 cm (1.0 in.). ePlug cavity at strut exit. fStrut inlet. ^Forward film manifold. hAft film manifold. 'Film cooled extension, 4.24 cm (1.67 in.) from apex. 'Distance from trailing edge, 0. 51 cm (0. 20 in.).

19 *T ft 0) in in en in *-t in en •»• in c- CO O •a en en cn co en co 1 N fe 111K « sa1 i 0 o o § M *, j, O C. o o o en CM d TH 1 n ii <-^ in in o i 0 0 CO CO CM i-l ^* S S O 0 O 0 1 CO d i d "' 14 i i .+oJ 13 -3 Q) in o 3 co in T3 CO Tf'

— I O CO a 1-1 CM O «-l CM o "g 5 CO CO <-t i-l EH d ^JS 1 0 0 0 O CO c d i" E 2 § a i d i" K o o S3 w a EH 0) ra ^ "N O N "S j-T o, CM : > O 3 o t-, C '" T-H B in o O CM co in X "S .2 ^ CO 00 CO CO CM CO O CO •*-» S o -> Q CO •8 O CD en oo en t- W l-( w fn Jr^ Q £ CO j; 53 "7 i— t o 0 M •3 -*J Q) r < en Q tsi <= t-c 0 fc. en a bD O tsi tl CD o d S Z S "\ O O £ H 00 CO CO CO > < P. t-, 1 CJ co en CM fl CM en U CD CO CO CO CO CM § 1) O O 0 0 (H •a I 1 s^o o O o S C rt 3 (H u o o 0 O O QJ ? ^ o Ifi REMEN T O a CD Q 0) !H *• O S 3 in in m in TJH "N M .2 ^ co in c- cq in co 1 g N w-* ^^ HI IS » co Ti- co in CO Tf" g k, "~ Oi a O. a J tT J3 0) CQ U en CM en CM en CM rt X3 o H E s d i-< d T+ O r-t s ?3 C o -M >> CO CD n^! "S d 0- W c- CO •V o > t. t, D 1 s "S rt CD -*-» & 'S 45 O d ^ •g PH S S i

20 C-69-2871 Figure 1. - Modified F-106B aircraft.

-Forward link

Rear link

nozzle

646.00 (254.33) Station 132.79 (52.58) 254.00 (100.00) Reference 528. 90 (208. 23) Wing rn_,,,a~ inlet leading edge station compressor face trailing edge CD-11187 28

Figure 2. - Schematic of test installation. (All dimensions are in cm (In.).)

21 C-71-1591 (a) J-85 dual throttle controls.

C-71-1595

(b) Cockpit display panel.

Figure 3. - F-106B cockpit arrangement.

22 Primary flap designation Cold internal Boattail diameter, angle, PR. cm (in.) deg Military 49.68(19.56) 17.28 + Reheat B 51.59(20.31) 13.40 Maximum afterburning 54.31(21.38) 7.57 Note: x = 0 is the assumed th roat P location on plug surface for the military flap. Station 537.69(211.69) T (5.43)

^- 650.34 608.20 646.00 (256.04) (239.45) (254.33)

CD-11188-28 Station 457.20 (180.00) 525.42 (206.86)

Figure 4. - Plug nozzle dimensions. (All dimensions are in cm (in.).)

23 Line description Quantity Outside diameter Wall thickness, cm (in.) cm (in.)

Compressor bleed air 4 3.81(1.5) 0.089(0.035) Strut plug and cooling air 3 2.54(1.0) .089 (.035) Primary flap cooling air 6 1.91 1.75) .089 (.035) a Distribution manifold 1 9. 80 by 3. 81 (3. 86 by 1.50) .165 (.065) flattened oval shape.

Strut and plug cooling air (three lines)-\ r Orifice holders for adjusting / coolant flows

Secondary airflow

Compressor bleed A •- air (four lines)

Hot Afterburner liner —.^ cooling air CD-11189-28

Distribution manifold J i-Forward film manifold

-Primary flap cooling air (six lines)

Figure 5. - Plug coolant flow paths.

24 vAft film manifold

Forward film y • L (coolant exit) manifold^,.

vFilm cooled extension Primary flow

Impingement pipe

0° Strut 9

Section B-B

120° Strut 240° Strut CD-11190-28

Section A-A

Figure 6. - Plug nozzle coordinate system used to locate instrumentation (see table I), (y Is distance along plug surface from plug front end.)

25 o Total pressure • Static pressure Centroids of equal ® Thermocouple projected areas"N* 45°

180° Primary flaps (typical) Looking upstream |— 0.63U.I 5 tfi25) Secondary flow pressure and temperatures (four each)

215' 180° 0.635 (0.25) Upstream view Station 513.21 (202.05) CD-11191-28 External shrouds (typical)

Figure 7. - Primary flap and external shroud instrumentation.

26 o Total pressure • Static pressure

Station 132.79 (52.28) 231 244 254 (91) (96) (100)

12° \\ (Looking upstream) // V_"^X CD-11192-28

Station 231 (91) Station 244 (96) Station 254 (100) (compressor face)

Figure 8. - Inlet and compressor face instrumentation.

Inner wall Outer wall with attached fins C-68-2360 Figure 9. - Plug nozzle inner and outer wall segments.

27 .A-Outer wall with attached fins

C-68-2363

Figure 10. - Segment of plug nozzle showing strut attachment surfaces.

PSeal retain- er clips

C-69-561

Figure 11. - Assembled plug segment showing seal retainer clips.

28 Thermocouples mounted directly through inner wall-)

Thermocouples in standpipe

' C-69-560

Figure 12. - Assembled plug segment showing typical thermocouple installation.

Outer wall halves with fins attached

Assembled strut inner strut structure C-68-2364

Figure 13. - Strut assembly.

29 C-70-6Q5 Figure 14. - Front of plug looking aft.

30 -71-2215 (a) Military primary.

(b) Reheat B+ primary. Figure 15. - Installed plug nozzle.

31 (c) Maximum afterburning primary; retracted shroud (x/l- -0.163).

Id) Maximum afterburn primary; intermediate shroud (x/l = 0.163).

-71-1698 (e) Maximum afterburn primary, extended shroud (x/!» 0.343).

Figure 15. - Concluded.

32 1 \ igle of attac k — Elevon deflec ion 3 25X1Q \ ^, \ *~\ 7 ^-— ,/i \ 1 x / / V, = 20 e 6 1 X\ 1 '"x / \ ^ "" — ' / \ 15 / \ f \ Angle-of-attack , a o r elevo n deflection 6 de g N 3 C D P O ^ t .6 .8 1.0 1.2 1.4 .6 .8 1.0 1.2 1.4 Flight Mach number, Mg (a) Altitude variation. (b) Angle-of-attack and elevon deflection variation. Figure 16. - Nominal aircraft and trajectory characteristics over flight profile.

Power setting Nozzle Exhaust Corrected Plug Total effective gas secondary coolant compressor throat tempera- weight to bleed to area, ature, flow ratio, primary primary ,AE8- T8- wVf flow ratio, "ow ratio, cm2 (In. ) D Maximum 1103 (171) 1806(3250) 0.065 0.04 0.057 afterburning O Reheat B+ 897 (139) 1444(2600) .032 .018 .018 O Military 729 (113) 956(1720) .032 0 Cf Adjusted performance at wV?= 0.032 ~~| Represents momentum of plug coolant based on properties at exit (station 608.20 cm (239.45 in.))

1.1

± 1.0

.4 .6 .8 1.0 1.2 1.4 Flight Mach number, M0 Figure 17. - Effect of power setting on performance over Mach number range. Re- tracted shroud (x/t =-0.163).

33 Mach Exhaust number, nozzle Mg pressure ratio,

O 0.9 3.35 D 1.2 4.50

2.5 3.0 3.5 4.0 4.5

Nacelle to primary throat area ratio, An/AE8

Figure 18. - Effect of primary throat area on nozzle gross thrust coefficient. Perfor- mance adjusted to corrected secondary weight flow ratio of 0.065. Coolant to primary

flow ratio, wc = w 0; retracted shroud (x/[ = -0.163). (See table II.)

Shroud position

O Retracted (x/l = -0.163) D Intermediate (x/l • 0.163) C> Extended (x/l =0.343)

1 1.0

.4 .6 .8 1.0 1.2 1.4 Flight Mach number, Mn

Figure 19. - Effect of shroud extension on performance at maximum afterburning power over Mach number range. Corrected secondary weight flow, 0.065; total compressor bleed to primary flow ratio, 0.058; plug coolant to primary flow ratio, 0.04.

34 1-0 "c 32 'o ir Mach Exhaust OJ 9 number, nozzle I ~- MO pressure 3 i .c S ratio, si „ PS'PO S .8 o 0.89 3.50 D 1.19 4.67 O .90 3.78 s Q 1.20 5.27 .7 .02 .04 .06 .08 .10 .02 .04 .06 10 Corrected secondary weight flow, uVr

(a) Military power; nozzle effective throat area, (b) Reheat B+; nozzle effective throat area, ' 729 square centimeters (113 in.2); exhaust 897 square centimeters (139 in.'); exhaust

gas temperature, 956 K (1720° R); coolant to temperature, 1444 K (2600° R); coolant to primary flow ratio, ac = wp = 0. primary flow ratio, wc = w. - 0.018.

Figure 20. - Effect of secondary weight flow on performance at nominal Mach numbers of 0.9 and 1.2. Retracted shroud Ml = -0.163).

Power Nozzle effective Mach Coolant to setting throat area, number, primary 1.0 MQ flow ra cm2 (in.2 + 0 O Reheat B 897 (139) 0.89 0.0 li m litary 723 (112) .88 0 J C/Ad justed performance at wvT= 0.032. 7/ c .9 $> 3 4 Exhaust nozzle pressure ratio,

Figure 21. - Effect of exhaust nozzle pressure ratio on performance with military and reheat B+ primary flaps, a nominal Mach number, Mg of 0.9 and a corrected secondary weight flow of 0.032. Retracted shroud (x/l= -0.163).

35 <• -I e_ C

CM

o n n r n 1 o o r> r n r 3 C 8 8") O 1 Snl — 0s o O O o 0 3 O o }

O o U (_ c o + ligh t Mac h number , M retracte d shrou (x/ l - -0 . 163 ) 5 . 8 1. 0 1 f l ;

.C

1 e>J c3 D ^3- CM "d CSJ C L ? S S 8 8 c> ss s C* °° 23 ^ s 3 '. ij iAra 8 ^= ,UID ' 3y 'OUBJ M( U 'MO|J }M6|3/V 8 'eajB pa x ' J. '3JnjB AJBLUUC 0} Ajepuooas "d/8d 'OIJBJ ^lsd 'OUEJ ajnssaji 3AJP3JJ3 -J3dlU3}SE6}SnBU.X3 iUB|003 6nid papa jj 03 3 inssajd 3|zzou isnEijxs Ajeiuud 0) AJEpuooas L g O O CD CD g

2 y *S3JV '"B3J' E '3.iniBJ3dWao^ j HX3 3A|p3jj3 se6 }snBUX3 Figur e 22 . - Engin an d coolan t flo w conditions

5 _/ \j u

Q Q •^

() C 3 ( (1 % \ 'n § 9i 8° O (. U u U O O o O D

O C . 8 1. 0 2 " U -0 . 163) ligh t Mac h number , M Q O C j o tar y power , retracte d shrou ( s-a

S £? S o o 3- cs. >c •^- CNJ ^ r CM o — 1 § O O O O O O C uio

S S S S S 8 J— I P^H •— I OQ pC ^o z'U! " y "^i "* <83V 'B3JB '3JnjEJ3dUJ3l

36 175 0 r^ dsB^effiBi <$i f 1 D> « 165

r 3500 a _ 3400 1 I o/ r > « [ ) 3300 1b c lo ft , c } 1 I fc 3200 d ^ ^e O

O i ( 8) 4a t P* P " TnW*^\ tal coolant, wc

/-\ ri n ftflBtCQBL i Jk n j Shroud position 3 ,^P 4 Strutse ndplugcot)lant, wn O Retracted M - -0.163) P D Intermediate (x/l • 0.163) O Extended (x/l-0.343)

•<.

{J

, aP * ifffi (^ A sn« c o *

0 2 primar y pressur e ratio , Pg/p p weigh t flow wV r flo w an d . area A£ cm c 8 pressur e i tf 3

ratio , P /p ta^

s 8 ^ £ Secondar y t o Exhaus nozzl e Correcte d secondar Plu g coolan primar ga s temperature , T K Effectiv exi q& ( 8 1 d ^ j \j i r o £ * > S <7 ! 8 c § .4 .6 .8 ^1.0 1.2 1.4 Flight Mach number, MQ (c) Maximum afterburning for various shroud positions. Figure 22. - Concluded.

37 S 2 8s 7 I csl .S •

2>.E *- ^ O eg |.f IS . I Illf-Il*ci|£s§?

5.S g §311

S1 Q_ 1st Q- Q- TO 1 ODO > 7 - IglsfT. L •js TT r^ E° ^ «

I -• :-^!i £§8 s

™ ,,-S =

oo Pj

~- BisgSA-^ Iff !:-3^

^§lS •£. S •i- • D> li S S

•j/j 'OUBJ isnjg)

38 Mach Exhaust nozzle Mach Exhaust noz !le number, pressure ratio, number, pressure ratio, M0 P8'PO M0 Primary flap configuration O 0.89 3.50 0 0.9 3.78 D 1.19 (D 4.67 1.2 5.27 O Reheat B+ - O Military

at Mn=0.89 >8at 0 9 • i~> -(tf O ^c O=r- ±AI 5^

-Prj/P8 at 1.19- ^p ^ -S 5^ P = 1.2 y s rt M0

.02 .04 .06 .08 .10 0 - .02 .04 .06 3.0 3.4 3.8 Corrected secondary weight flow, Wi Exhaust nozzle pressure ratio, (a) Military power,- nozzle effective throat area, (b) Reheat B+; nozzle effective throat area, 2 2 729 square centimeters (113 in. ); exhaust 897 square centimeters (139 in. ); exhaust (c)Mach 0.90; corrected gas temperature, 956 K (1720° R); coolant to gas temperature, 1444 K (2600° R); coolant secondary weight flow primary flow ratio, wc« &;_, 0; retracted to primary flow ratio, wc = w., 0.018; re- ratio, 0.033; retracted shroud, (x/l= -0.163). tracted shroud (x/l = -0.163): shroud (x/t- -0.163).

1.1 Os Primary flap Corrected Q, \?*s' \ . configuration secondary %,1.0 ^*^O weight flow ratio, ^ W-/U ^^N\s D Maximum 0.063 \ afterburning O Reheat B+ 0.019-0.069 \s O Military .022-0.09 r^ 4 8 12 _16

Secondary flow parameter, (w$VTs)/Ps

(d) Mach 0.90; retracted shroud (x/l- -0.163). Figure 24. - Pumping characteristics.

39 Static values Flight values Exhaust gas temperature, Tg, K(°R) 1580(3025) 1794(3230) Exhaust gas pressure, Pg, atm 1.78 1.57 Exhaust gas weight flow, Wg, kg/sec (Ib 18.95(41.78) 15.65(34.52) Exhaust nozzle pressure ratio, P0/p0 3.32 3.37 Corrected secondary weight flow ratio, 0.052 0.063 Plug coolant to primary flow ratio, w. 0.035 0.040 Mach number, M0 0.90 D Plug wall O Plug coolant Open symbols denote static values (ref. 10) Solid symbols denote flight values 1800 1000 n

1600 900 I () I- ° 80 n .- '1400 in* ° -«£]

700 = 1200

500& 0 .2 .4 .6 .8 1.0 1000 ~ Dimensionless distance along plug surface, y/L Figure 25. - Coolant and plug wall temperature variations - static and flight data. Maximum afterburning configuration; retracted shroud (x/l - -0.163).

40 Primary flap Plug to coolant Exhaust gas weight flow, Type of data configuration primary flow wg, ratio- kg/sec (Ibm/sec)

O Maximum afterburning 0.035 9.5 21 "I Static O .035 14.1 31 Mref. 10) A .035 19.1 42 J .040 14.1-15.9 31-35 ~\ A• 1 .040 18.1-21.3 40-47 Flight • ReneatB+ .018 15.0-15.9 33-35 I * Reheat B+ .018 19.1-22.7 42-50 J 1800,— 1000 £ t • ^ ra / ^^ s om •( • *" i ^^ ^ = <* 1600 / 9 A^ £ + ^^ Reheat B / R ^"•fl X A s ^ . X ,^ Qtfirt m RIY1 fc rnkl W ^ - Cn ^ ° / 3 1400 *° H? 1 ^> r£•" > i Maximum afterburnina ro "M? s xrfcfflT o 700 ,1^K" M* 1200 01 o # -' ^ ^ 600 1100 1200 1300 1400 1500 1600 1700 1800 1900 20 Exhaust gas temperature, T8, K.

I I I 2000 2200 2400 2600 2800 3000 3200 3400 3600 Exhaust gas temperature, Tg, °R Figure 26. - Effect of exhaust gas temperature on plug throat wall temperature - static and flight data, retracted shroud (x/l = -0.163).

i i ] Primary flap ^ 1700 D^ X1 900 S w^) S „- ; 'Tr'lugvvail £ £ 1500 re -i-* -^ 800 r^ £ S. ^ "^ g, e i" 1300 ^ 7fin HOD 1200 1300 1400 1500 1600 Exhaust gas temperature, T8, K

2000 2200 2400 2600 2800 Exhaust gas temperature, Tg, °R Figure 27. - Effect of exhaust gas temperature on throat wall temper- ature. Mach 0.9; corrected secondary weight flow ratio, 0.033; coolant to primary flow ratio, ac = w., 0.018; nozzle effective throat area, 897 square centimeters U39 in.'); exhaust nozzle pressure ratio, 3.29 to 3.81; reheat B+primary flap; retracted shroud (x/l = -0.163).

41 200U -O *^ "^.»- aco (• 1 I Primar y fla p ski n temperature , T K I ^ w .02 .04 .06 .08 Corrected secondary weight flow, wVr Figure 28. - Effect of secondary weight flow on primary flap skin temperature. Reheat B+; nozzle effective throat area, 897 square centimeters (139 in.2); exhaust gas temperature, 1444 K (2600° R); Mach 0.9; retracted shroud (x/l = -0.163).

Assembly station (coolant exit) a (compressor discharge) k I I

CD-11189-28

Figure 29. - Plug coolant flow path and measuring stations.

42 Assembly station: Compressor discharge a b

O Coolant pressure O Coolant temperature D Plug skin temperature A Primary flap temperature 1100 2000 120 1000 1800 100 900 1600

80 800 1400

60 700 1200

40 600 1000

20 500 800 8 400 •5 0 I ,(a-l) Mach 0.39; exhaust nozzle pressure (a-2) Mach 0.69; exhaust nozzle pressure S. s. ratio, 2.47; exhaust gas temperature, ratio, 3.05; exhaust gas temperature, & 1515 K (2727° R); nozzle effective throat 1421 K (2557° R); nozzle effective throat area, 899.4 square centimeters (139.4 area, 885.8 square centimeters (137.3 in.'); corrected secondary weight flow in.2); corrected secondary weight flow ratio, 0.052. ratio, 0.031. 1100 2000 «§ 120 ,— ° 1000 1800 100 900 1600 80 800 1400 60 700 1200 40 600 1000 20 500

±PO_|_| 400 a b c d e f g hi k I a bed e f Assembly station

I I I I I I I I I I I 0 .2 .4 .6 .8 1.0 1.2 1.4 0 .2 .4 .6 .8 1.0 1.2 1.4 Distance along plug surface, y/L

(a-3) Mach 0.89; exhaust nozzle pressure (a-4) Mach 1.01; exhaust nozzle pressure ratio, 3.75; exhaust gas temperature, ratio, 4.27; exhaust gas temperature, 1462 K (2631° R); nozzle effective throat 1426 K (2567° R); nozzle effective throat area, 885.2 square centimeters (137.2 area, 883.9 square centimeters (137.0 in.2); corrected secondary weight flow in.2); corrected secondary weight flow ratio, 0.032. ratio, 0.031.

+ (a) Reheat B ; coolant to primary flow ratio, ac - a 0.018; retracted shroud (xrt - -0.163).

Figure 30. - Coolant characteristics and metal temperatures.

43 Assembly station: Compressor discharge Coolant exit a b k t

O Coolant pressure O Coolant temperature D Plug skin temperature A Primary flap temperature 1100 2000 120 r— 1000 1800 g. i<: *>- £ 900 I _1600 | Cg. 8. 1400 ^

700 1 —1200 600 I 1000 500 800 400 a b c d e f g hi j Assembly station

I I I I I I I 0 .2 .4 .6 .8 1.0 1.2 1.4 Distance along plug surface, y/L (a-5) Mach 1.30; exhaust nozzle pressure ratio, 5.81; exhajst gas temperature, 1521 K (2737° R); nozzle effective throat area, 882.5 square centimeters (136.8 in.2); corrected secondary weight flow ratio, 0.059. (a) Concluded. 1100 -,2000 120, 1000 -1800 ^ o: o 100 o> 900 » . - 1600 | i 800 I -1400 | i 700 - 1200 ™ 1 ' "c •i 40 J5 >00 3I 5 -1000 ^ § 20 500

0 400 a b c d e f g hi Assembly station

I I I I I II I I I 0 .2 .4 .6 .8 1.01.2 1.4 0 .2 .4 .6 .8 1.0 1.2 1.4 Distance along plug surface, y/L (b-1) Mach 0.38; exhaust nozzle pressure lb-2) Mach 0.69; exhaust nozzle pressure ratio, 2.23; exhaust gas temperature, ratio, 2.79; exhaust gas temperature, 1967 K (354tf> R); nozzle effective throat 1824 K13283° R); nozzle effective throat area, 1130.3 square centimeters (175.2 area, 1101.3 square centimeters (170.7 in.2); corrected secondary weight flow in.2); corrected secondary weight flow ratio, 0.049; total coolant to primary flow ratio, 0.056; total coolant to primary flow ratio, 0.058; plug coolant to primary flow ratio, 0.057; plug coolant to primary flow ratio, 0.04. ratio, 0.040. (b) Maximum afterburning; retracted shroud (x/l • -0.163). Figure 30. - Continued.

44 Assembly station: Compressor discharge a b

O Coolant pressure O Coolant temperature D Plug skin temperature A Primary flap temperature 1100 -i 2000 120 1000 - 1800 100 £ 900 s_ 1600 I I s -1400 I -60 S 700 - 1200 to "c I 40 600 - 1000 i 20 500

0 t"0 I-I400 a b c d e k I a bed ef Assembly station

I I I I 0 .2 .4 .6 1.0 1.2 1.4 0 .2 .4 .6 .8 1.0 1.2 1.4 Distance along plug surface, y/L (b-3) Mach 0.90; exhaust nozzle pressure (b-4) Mach 0.98; exhaust nozzle pressure ratio, 3.37; exhaust gas temperature, ratio, 3.64- exhaust gas temperature, 1794 K (3230° R); nozzle effective throat 1780 K (3204° R); nozzle effective throat area, 1091.6 square centimeters (169.2 area, 1101.9 square centimeters (170.8 in.2); corrected secondary weight flow in.2); corrected secondary weight flow ratio, 0.063; total coolant to primary ratio, 0.067; total coolant to primary flow ratio, 0.058; plug coolant to primary flow ratio, 0.058; plug coolant to primary flow ratio, 0.040. now ratio, 0.041.

1100 2000 120

1000 - 1800 100 900 g" _ a 1600 ^80 800 § 1400 I 60 700 1 £ 1200

I I I I I I I I 0 .2 .4 .6 .8 1.0 1.2 1.4 Distance along plug surface, y/L (b-5) Mach 1.29; exhaust nozzle pressure ratio, 491; exhaust gas temperature, 1884 K (3391° R); nozzle effective throat area, 1116.8 square centimeters (173.1 in.2); corrected secondary weight flow ratio, 0.069; total coolant to primary flow ratio, 0.058; plug coolant to primary flow ratio, 0.041.

Ib) Concluded. Figure30. -Continued.

45 Assembly station: Compressor discharge a b

O Coolant pressure O Coolant temperature D Plug skin temperature A Primary flap temperature 1100 ~ 2000 120r— 1000 — 1800 100- 900 _ 1600 80 — 800 1400 60- 700 — 1200 40- 600 — 1000 500 cc 20- o ^ —800 g J 400 £ J5 (c-1) Mach 0.69; exhaust nozzle pressure (c-2) Mach 0.90; exhaust nozzle pressure E S. ratio, 2.71; exhaust gas temperature, ratio, 3.33; exhaust gas temperature, 8. £ 1784 K (3211° R); nozzle effective throat • 1834 K (3302° R); nozzle effective throat area, 1105.8 square centimeters (171.4 area, 1105.2 square centimeters (171.3 2 in.2); corrected secondary weight flow in. ); corrected secondary weight flow ratio, 0.060; total coolant to primary flow ratio, 0.065; total coolant to primary flow ratio, 0.057- plug coolant to primary flow ratio, 0.059; plug coolant to primary flow ratio, 0.040. ratio, 0.041. iioo a ~ 2000 120.— 1000 — 1800 100 — 900 _ 1600 80 — 800 _ 1400 60 — 700 — 1200 40 — 600 1000 — 20 — 500 — 800 0 — 400 a b c d e f g a b c d e f g hi Assembly station

I I I I I I I I I I I I I 0 .2 .4 .6 .8 1.0 1.21.4 0 .2 .4 .6 .8 1.01.2 1.4 Distance along plug surface, y/L (c-3) Mach 1.04; exhaust nozzle pressure (c-4) Mach 1.30; exhaust nozzle pressure ratio, 3.86; exhaust gas temperature, ratio, 4.91; exhaust gas temperature, 1799 K (3239° R); nozzle effective throat 1882 K (3387° R); nozzle effective throat area, 1103.2 square centimeters (171.0 area, 1112.9 square centimeters (172.5 in.2); corrected secondary weight flow in.2); corrected secondary weight flow ratio, 0.066; total coolant to primary flow ratio, 0.069; total coolant to primary flow ratio, 0.057; plug coolant to primary flow ratio, 0.058; plug coolant to primary flow ratio, 0.040. ratio, 0.041.

(c) Maximum afterburning; intermediate shroud (x/l = 0.163).

Figure30. -Continued.

46 Assembly station-. Compressor discharge Coolant exit j k l

O Coolant pressure O Coolant temperature D Plug skin temperature A Primary flap temperature 2000 120 p 1800 100 • 1600 80 • 1400 60- 1200 40 • 1000 20 - 800

(d-1) Mach 0.69; exhaust nozzle pressure (d-2) Mach 0.89; exhaust nozzle pressure a. ratio, 2.71; exhaust gas temperature, ratio, 3.28; exhaust gas temperature 1825 K (3285° R); nozzle effective throat 1847 K (3324° R); nozzle effective throat area, 1112.3 square centimeters (172.4 area, 1112.3 square centimeters (172.4

-in.2); corrected secondary weight flow in.2|; corrected secondary weight flow ratio, 0.061; total coolant to primary flow ratio, 0.066; total coolant to primary flow ratio, 0.056; plug coolant to primary flow ratio, 0.059; plug coolant to primary flow ratio, 0.039. ratio, 0.041. —,1100 2000 2 120 S 1000 - 1800 100 900 _ 1600 80 800 1400 60 700 1200

40 600 1000 20 500 800 0 J-l400 a b c d e Assembly station I I I I I I I I I I I I I 0 .2 .4 .6 1.0 1.2 1.4 0 .2 .4 .6 .8 1.0 1.2 1.4 Distance along plug surface, y/L

(d-3) Mach 0.98; exhaust nozzle pressure (d^4) Mach 1.28; exhaust nozzle pressure ratio, 3.55; exhaust gas temperature, ratio, 4.78; exhaust gas temperature, 1789 K (3220? R); nozzle effective throat 1882 K (3387° R); nozzle effective throat area, 1106.4 square centimeters (171.5 area, 1120.0 square centimeters (173.6 in.'); corrected secondary weight flow in.2); corrected secondary weight flow ratio, 0.068; total coolant to primary flow ratio, 0.070; total coolant to primary flow ratio, 0.057; plug coolant to primary flow ratio, 0.057; plug coolant to primary flow ratio, 0.040. ratio, 0.040.

(d) Maximum afterburning; extended shroud (x/l • 0.343).

Figure30. -Concluded.

47 <>-x \

Nominal Coolant throat ex\\ plane .2 .4 .6 1.0 1.2 1.4 0 .2 .4 .6 .8 1.0 1.2if f1.4 Distance along plug surface, y/L (a-1) Mach 0.39. (a-2) Mach 0.69.

i.C.

1.0 \ ( L .9 Jh

.8 c \

.7 \

.6 a T .5 I1 A9 r ~-~* •O .3 i / \ 1 1 \ -o -^ ^ -PO No nin< 1 I 1 -b Coolant .2 th roat 8 J exit plan i ipex '© •\ .2 .4 .6 .8 1.0 1.2 1. Distance along plug surface, y/L (a-3) Mach 0.89. + (a) Reheat B ; retracted shroud (x/l • -0.163). Figure 31. - Pressure distribution along plug surface.

48 1.1

/R V 2^

Nominal Coolant r e rat i "throat exit plane~ -Apex

.2 .4 .6 .8 1.0 1.2 1.4 0 .2 .4 .6 Distance along plug surface, y/L

(a-4)Mach 1.01. (a-5)Machl.30. (a) Concluded. 1.2

i

.9

.8

.7

.6 P

.5 /o /^ PO .4

Nominal Coolant .3 "throat "exit plane" "Apex

.2 .4 .6 .8 1.0 1.2 1.4 0 .2 .4 .6 .8 1.0 1.2 1.4 Distance along plug surface, y/L (b-l)Mach0.38. (b-2)Mach0.69.

(b) Maximum afterburning; retracted shroud (x/l= -0. 163).

Figure 31. -Continued.

49 1.1 f O ^ ~ o

% O

3 -3 .4 ft

.3 PO -PO Coolant .2 Nominal ( Nominal i 'throat "exit plane" ~Apex throat "Apex .Coolant exit plane .1 .2 .4 .6 .8 1.0 1.2 1.4 0 .2 14 .6 .8 1.0 1.2 1.4 Distance along plug surface, y/L (b-3) Mach 0. 90. (b-4) Mach 0. 98.

1.2

•a. cT .7

.6

B -5 _o I •5 .4

PO

Nominal Coolant 'throat exit plane- "Apex

.2 .4 .6 .8 1.0 1.2 1.4 Distanre alona plug surface, y/L (b-5) Mach 1.29.

to) Concluded.

Figure 31. - Continued.

50 1.1

( 1.0

.9

.8

.7

.6

.5

.4 \JL -PO- .3

Coolant .2 "3. Nominal -exit plane- -Apex throat .s"

.1 (c-1) Mach 0.69. (c-2)Mach0.90.

8

Nominal Coolant "throat "exit plane" Apex'

.6 .8 1.0 1.2 1.4 0 .2 .4 .6 1.0 1.2 1.4 Distance along plug surface, y/L (c-3) Mach 1.04. (c-4) Mach 1.30.

(c) Maximum afterburning; intermediate shroud (x/l= 0.163).

Figure 31. - Continued.

51 1.1

1.0

.9

.8

.7

.6

:PO

.Nominal^ _ Coolant throat exit plane Apex

(d-l)Mach0.69. (d-2) Mach 0.89.

.9

PO .Nominal J 7 Coolant throat exit plane Apex Apex _Nominalj Coolan:it)01dlplanHt e I I throat exiti , IT '0 .2 .4 .6 .8 1.0 1.2 1.4 0 .2 .4 .6 .8 1.0 1.2 1.4 Distance along plug surface, y/L

(d-3) Mach 0.98. (d-4) Mach 1.29.

(d) Maximum afterburning; extended shroud (xft • 0.343).

Figure31. -Continued.

52 .2 .4 .6 .8 1.0 1.2 1.4 0 .2 .4 .6 .8 1.0 1.2 1.4

(e-3) Mach 1.02. (e-4) Mach 1.19.

(e) Military power; retracted shroud (x/l - -0.163).

Figure 31. - Concluded.

53 20

O Reheat B+ primary D Maximum afterburn CD- 15 primary Solid symbols denote after- burner light-off MO Open symbols denote no afterburner light

.2 .4 .6 .8 Simulated flight Mach number, Mg

Figure 32. - J85 afterburner ignition limits with fixed exit areas obtained in altitude cell. Percent of rated engine rotor speed, 80; compressor inlet temperature, 294 K (530° R).

Compressor inlet temperature,

K(°R)

Compressor high stress region

100 102 104 10^6 108 110 Physical speed, %Np

Figure 33. - J-85 transient with simulated maximum afterburning flame-out. Engine speed, 99 percent of rated turbine discharge temperature, 984 K (1770° R) before flame-out. Mechanical governor

flat at 99.8 %NR; overspeed trip at 100.5 %NR.

54 NASA-Langley, 1972 28 E-6676 NATIONAL AERONAUTICS AND SPACE ADMiSTRATiOtNT *1lN0TON, • 20546 , ^aMB^ ;.«•':';•-'-*'' hftJS >-•. ' '• ."•*-,•;•'?;•'• POSTAGK*)

; :OFFICtAI- BUSlHES^j;; •; ' FfRST CLASS MAIL"^'^''" SPACE AOMiN.srf^Ttorf"- PENAUTY FOR PRIVATF: USE S30O " " * ' '.~;.:"':'

If Undeitvct^Hc : |&B*3J HI posraj MjaujJ) 00 KrM Rs,r, , |

aeronaii/ictil and space activities of the United Stales shall be conducted so as to cor.' 'bute. . . t.o the expansion of hua',in i^u/l~\ edge:&j:p(K'ttQinena in Stye titmt/ipkere and. space. Tim Administration. shall pt oi'idv for the widest .pfat'th'able- and appfipffat? dissemination, of ittfwuation concerning its ,ia-r;-tties and the •-f.r^n' ~!<<:reQ\" v;;^--x> — NATIONAL AERONAUTICS AND SPACE ACT OF 1958;

NASA. SCIENTIFIC AND TECHNICAL

J;lEGHNICAL REPORTS: Scientific and ' •"' ^ TR ANSI. ATIONS;! Information /technical information coasidered important, published «o a foreign language consklered' complete, and a lasting contribution to existing to merit NASA distrtbtition in'English. ^knowledge, ' • SPECIAL PUBLICATIONS: Information TECHNICAL NOTES: Information less broad derived from or of value to NASA activities. in scope but nevertheless of importance as a Publications include conference proceedings, contribution to existing knowledge. ; r monographs, data compilations, handbooks, ' sourceboofcs, and special biblk»}i:raphies; '• • • TECHNICAL MEMORANDUMS: Information receiving limited distribution TECHNOLOGY UTILIZATION because of preliminary data, security classifica- PUBLICATIONS: Information on technology tion, or other reasons;; used by tJASAithat may be of particttbr interest in commercial and other fton- CONTRACTOR REPORTS: Scientific aia? applications. Publications includelEfGJh Briers, informatiottgenerated under a JNAS A Technology Utilization Reports and or grant anEf pnsidered an important Technology Surveys. /contribution to exiMiflg knowledge. ; ^

Details oh the availability t>f these publications may be obtained from: SCIiNjriFIC AND TECHNICAL INFORMATION OFFICE

NATIONA|S|\ERONAUT^S AND SFAP ADMIKiSTRATtON , DX.