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1 TO: FROM: TO: UNCLASSIFIED AD NUMBER ADA CLASSIFICATION CHANGES unclassified restricted LIMITATION CHANGES Apprved fr public release; distributin is unlimited. FROM: Distributin authrized t DD nly; Administrative/Operatinal Use; 19 MAY Other requests shall be referred t Natinal Aernautics and Space Administratin, Washingtn, DC. Pre-dates frmal DD distributin statements. Treat as DD nly. AUTHORITY NACA research abstracts n. 57 dtd 29 Jan 1954; NASA TR Server website THIS PAGE IS UNCLASSIFIED

2 ^qt-t-j: MÄV NACA UNCLASSlFIEEiPrN. RM N. E7C12 A 4>-f6& ~$rf tä'ftwfr *jk -Ge^. äjff 'Z- RESEARCH MEMORANDUM ALTITUDE -WIND-TUNNEL INVESTIGATION OF THRUST AUGMENTATION OF A TURBOJET ENGINE n - PERFORMANCE WITH WATER INJECTION Q AT COMPRESSOR INLET UJ UJ By Rbert O. Dietz and William A. Fleming gj J Flight Prpulsin Research Labratry <r Cleveland, Ohi O CLASSIFIED DOCUMENT This dcument cntains classified infrmatin affecting the Ratinal Defense f the United States within the meaning f the Espinage Act, USC 50:31 and 32. Its transmissin r the revelatin f its cntents is any manner t an unauthrised persn is prhibited by la«. Infrmatin s classified may he imparted nly t persns in the military and naval Services f the United States, apprpriate civilian fficers and em-?lyees f the Federal Gvernment «h have a legitsate Interest therein, and t united States citizens f knwn lyalty and discretin wh f necessity must be infrmed theref. U. CO CO O 3UJ VjjeSj NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS ^ WASHINGTON May 19, 1947 JESTRICTED <& ^W ^^aklotf. *_ UNCLASSIFIED tftf^**

3 NASA Technical Library UNCLASSIRFC NACA EM N. E7C12 ""I 11 «,-«~«^ ^-.A NATIONAL AOTISORY CCMÖTTEE FOR AERONAUTICS RESEARCH MEMORANDUM ALTITUDE-WIND-TUNNEL INVESTIGATION OF THRUST AUGMENTATION OF A TURBOJET ENGINE II - PERFORMANCE WITH WATER INJECTION AT COMPRESSOR INLET By Rbert 0. Dietz and William. A. Fleming SUMMARY Thrust augmentatin f a standard turbjet engine "by water injectin at the inlet f the axial-flv cmpres'blsrhas been investigated in the Cleveland altitude wind tunnel. Engine perfrmance at an engine speed f 7600 rpm was btained ver a wide range f water-air ratis at pressure altitudes f 5000 and 20,000 feet and at a rampressure rati crrespnding t a flight Mach number f abut A fixed-area tail-pipe nzzle 16^- inches in diameter was used fr this investigatin. Data are presented t shw the effect f water injectin n engine perfrmance. A discussin f the effect f water injectin n the pressure and temperature distributin at the cmpressr utlet f the turbjet engine is inluded. At flight cnditins fr which the inlet air must be heated t avid icing during the prcess f water injectin, thrust augmentatin by the use f water injectin is nt practical. The net thrust f the engine with an inlet-air temperature f 520 R at a pressure altitude f 5000 feet was increased 15 "percent by means f water injectin in the cmpressr inlet at a water-air rati'f Ö.0407 and a simulated flight Mach number f The specific liquid cnsumptin, defined as the punds f fuel and water cnsumed by the engine per pund f net thrust, was 220 percent greater than the specific fuel cnsumptin fr the engine withut water injectin. These netthrust and specific-liquid-cnsumptin data represent engine peratin at limiting turbine-utlet temperature (1680 R). Water injectin markedly changed the pressure, temperature, and velcity distributins at the cmpressr utlet. UNCLASSIFIED

4 MCA RM N. E7C12 INTRODUCTION Thrust augmentatin is f imprtance in increasing the usefulness and the range f applicatin f turbjet engines. An investigatin f thrust augmentatin by varius methds is in prgress at the NACA Cleveland labratry. Three methds f thrust augmentatin have been investigated: (l) tail-pipe burning, (2) water Injectin, and (3) bleed-ff cycle cmbined with water injectin. The results f investigatins f tail-pipe burning n a turbjet engine are presented in references 1 and 2. The injectin f water int the inlet f a turbjet engine increases the thrust Df the engine by increasing the mass flw thrugh the engine and decreasing the temperature f the air flwing thrugh the cmpressr as the water vaprizes. The lwer temperature f the air flwing thrugh the cmpressr increases the cmpressr pressure rati by increasing the cmpressr Mach number and als increases the difference between the temperatures at which the wrk f cmpressin is added t and taken frm the wrking fluid in the engine. Results f an investigatin f water injectin at the inlet f a turbjet engine having an axial-flw cmpressr are reprted. This investigatin was made at a ram-pressure rati crrespnding t a flight Mach number f at pressure altitudes~f 5000 and 20,000 feet. The water-air rati was varied frm 0 t at 3000 feet and frm 0 t Ö.0677 at 20,000 feet while the engine speed was maintained at 7600 rpm. A fixed-area tall-pipe nzzle was used n the engine. Perfrmance results with water injectin at the cmpressr inlet f a standard turbjet engine and a discussin f the effect f water injectin n the pressure, temperature, and velcity distributins at the cmpressr utlet are presented. INSTALLATION FOE VATER INJECTION A standard turbjet engine having an 11-stage axial-flw cmpressr, eight cylindrical cmbustin chambers, a single-stage turbine, a tail pipe, and an exhaust nzzle was used in this investigatin. The verall length f the engine is 14 feet and the maximum diameter is 36 inches.

5 NACA EM N. E7C12 Water was Injected at a statin 6 inches upstream f the engine inlet thrugh 24 nzzles installed circumferentially arund the inlet duct, (See fig. 1.) Very fine drp size was desirable in rder t avid ersin f the cmpressr blades. The cmmercial air-atmizing spray nzzle used t inject the vater is shewn in figure 2. This nzzle has an air jet in the center that is inch in diameter and a main rifice diameter f inch. Water is intrduced thrugh the annular passage in the nzzle where swirl is induced by several turning vanes. Air discharged frm the center jet strikes the water inside the miring chamber just befre entering the rifice and the mixture is discharged in the frm f a fine spray. With a water pressure f 60 punds per square inch and an air pressure f 100 punds per square inch, the drp size f the resulting spray is apprximately 50 micrns. WIND-TUNNEL INSTALLATION AND TEST PEOCEDUEE The engine was suspended frm a wing sectin installed in the 20-ft-diameter test sectin f the altitude wind tunnel. Dry air was supplied t the engine thrugh a duct frm the tunnel make-up air system. A frictinless labyrinth slip jint in the inlet-air duct 40 feet upstream f the engine inlet made pssible the measurement f thrust with the wind-tunnel balance. The air was thrttled frm apprximately sea-level pressure t the desired pressure at the engine inlet while the pressure in the wind-tunnel test sectin was maintained at the desired pressure altitude. The temperature f the air supplied t the engine was maintained at apprximately 520 B in rder t prevent icing when water was injected. This investigatin was cnducted at pressure altitudes f 5000 and 20,000 feet and a ram-pressure rati f 1.05, which crrespnds t a flight Mach number f At bth pressure altitudes, the engine was 'perated at a speed f 7600 rpm and data were btained at varius water flws. A maximum water flw f 2.65 punds per secnd was limited by the pumping equipment. A fixed-area tail-pipe nzzle 16*- inches in diameter was installed n the engine. ^ A survey rake was munted in the inlet duct upstream f the engine inlet t measure temperatures and pressures frm which the air flw was calculated. The pressure and the temperature f the gases were measured at several statins in the engine (fig. 3) and thrust was determined frm the balance scales. The methds used t calculate thrust and air flw are presented in the appendix. The engine was perated with kersene (AN-F-32).

6 NACA RM W. E7C12 DISCUSSION OF RESULTS Engine Perfrmance The effect f water injectin n the perfrmance f a turbjet engine with.a fixed-area tail-pipe nzzle at pressure altitudes f 5000 and 20,000 feet and a flight Mach number f is shwn in figures 4 t 11. The relatin between water-air rati and tailpipe-nzzle utlet ttal pressure and'temperature is shwn in figure 4. Thrughut mst f the range f water-air ratis investigated, the ttal temperature f the gas at the tail-pipe-nzzle utlet was belw the limiting value (1680 B). With the fixed-area tail-pipe nzzle used in this investigatin, the tail-pipe ttal temperature was higher than the limiting value at very lw and very high' waterair ratis. In rder t maintain limiting tail-pipe temperature and thereby btain the maximum available thrust at all water-air ratis, a variable-area tail-pipe nzzle shuld be used. The effect f water injectin n jet thrust, net thrust, percentage increase in net thrust, fuel cnsumptin, air flw, fuel-air rati, and specific fuel and liquid cnsumptin is shwn in figures 5 t 11. At limiting tail-pipe temperatures and at a simulated flight Mach number f 0.265, the net thrust was increased 15 percent at a pressure altitude f 5000 feet and a water-air rati f and 12 percent at a pressure altitude f 20,000 feet and a water-air rati f (fig. 7). The respective specific liquid cnsumptins under these cnditins were 220 and 280 percent greater than the specific fuel cnsumptin withut water injectin (fig. 11). The data discussed in the previus paragraph indicate that water injectin affrds limited gains in thrust accmpanied by large increases in specific liquid cnsumptin. As previusly mentined, an inlet-air temperature f apprximately 520 R was maintained during the water-injectin investigatin in rder t avid icing at the engine inlet. Fr the flight cnditins investigated at a pressure altitude f 20,000 feet, this temperature was cnsiderably higher than the standard atmspheric temperature at that altitude. The engine thrust was therefre reduced. Calculatins shw that if the cmpressr-inlet temperature was maintained at the NACA standard value crrespnding t an altitude f 20,000 feet, the net thrust f the engine with n water injectin wuld be 13.5 percent higher than the thrust btainable at limiting turbine-utlet temperature with water injectin and an inlet-air temperature f 520 R. Thus fr flight cnditins at which the inlet air must be heated t avid icing during the prcess f water injetin, thrust augmentatin by the use f water injectin is nt practical.

7 HACA EM N. E7C12 5 Engine-Cmpnent Perfrmance An. analysis f temperature and pressure surveys at several statins in the engine has been made t determine the effect f water injectin n the engine cmpnents. The data shw that water injectin had n apparent effect n cmbustin efficiency and turine efficiency thrughut the range f water-air ratis investigated at pressure altitudes f 5000 and 20,000 feet. Cmbustin-efficiency data are presented in figure 12 and the methd used t determine cmbustin efficiency is explained in the appendix. Turbine efficiency culd nt be accurately calculated, but as an indirect apprach the data were pltted n a turbine characteristic curve (fig. 13) determined frm a previus investigatin f the engine in the altitude wind tunnel. It is assumed that injectin f water des nt affect these characteristics. Because the turbine perating pints with water injectin fell between the 78-percent and 80-percent efficiency cnturs, in figure 13, it is cncluded that the turbine efficiency remained essentially cnstant. Cmpressr perfrmance culd nt he accurately determined because f the nnunifrm temperature and pressure distributin acrss the cmpressr-utlet annulusas well as the nnunifrm distributin f water vapr at the cmpressr utlet. An analysis f the changes in cmpressr-utlet pressure, temperature, and velcity distributins results, hwever, in the frmatin f tentative estimates regarding cmpressr perfrmance. Althugh limited in scpe, the temperature and pressure surveys btained shw the imprtant effects f water injectin n the flw thrugh the cmpressr. Average cmpressr-utlet pressures, temperatures, and ttalpressure ratis fr different perating cnditins are shwn in figures 14 and 15. These temperatures and pressures were integrated with respect t the mass-flw distributin at.the cmpressr utlet. This methd f integrating the temperatures and pressures is fully discussed in the appendix. The cmpressr-utlet ttal and static pressures increased and the ttal temperature decreased as the waterair rati was increased (fig. 14). The cmpressr ttal-pressure rati increased with water-air rati (fig. 15). Surveys f temperature, pressure, and velcity at the cmpressr utlet are shwn in figures 16, 17, and 18, respectively, fr varius water-air ratis at pressure altitudes f 5000 and 20,000 feet. Large variatins in temperature, ttal pressure, and velcity distributin at the cmpressr utlet indicate a wide departure frm the design perating cnditins f the cmpressr

8 KACA RM N. E7C12 blading. The cmpressr-utlet temperatures are lver at the blade tips than at the blade rts when water is injected, which indicates that the centrifugal actin f the cmpressr thrws the water tward the blade tips. (See fig. 16.) Changes in ttal- and staticpressure distributins at the cmpressr utlet fr varius waterair ratis.with a unifrm cmpressr-inlet ttal-pressure distributin are shwn in figure 17» Cmpressr-utlet velcity distributins were markedly changed by water injectin as shwn in figure 18. These velcities were calculated by substituting values f temperature and pressure btained frm figures 16 and 17 int the cmpressible-flw-velcity equatin. S lng as the flw cnditins ver the cmpressr blading d nt deviate very far frm the design cnditins, water injectin shuld imprve the adiabatic cmpressr efficiency because vaprizatin f the water reduces the temperature during cmpressin. As the water-air rati was increased, the vlume flw thrugh the last few stages f the cmpressr decreased as indicated by the decrease in axial velcity at the cmpressr utlet. As a result, the effective angle f attack f the blades in the latter stages increased because the rtatinal"velcity was nt changed. Because at design cnditins axial-flw-cmpressr blading perates as highly laded airfils, a small increase in the angle f attack f sme f the blades wuld decrease the cmpressr efficiency and pssibly cause sme f the blading t reach a cnditin f stalling. At the same time, the decrease in temperature f the fluids flwing thrugh the cmpressr increases the blade Mach number. If the Mach number reaches t high a value, cmpressibility lsses may ccur ver the blades and cause a decrease in cmpressr efficiency. An example f a cnditin at which the. cmpressr blades in the latter stages are prbably stalled is a water-air rati f and a pressure altitude f 20,000 feet (fig. 16(b)). At this cnditin, the temperature distributin acrss the cmpresr-utlt amiulus was almst unifrm instead f varying as at lwer water-air ratis. This test cnditin was later rpeated and the unifrm temperature distributin was again bserved. This unifrm distributin indicatec mixing f the tw fluids at sme pint in the cmpressr, which may have been the result f cmpressr-blade stall. Changes in cmpressr efficiency are indicated by the relatin between water-air rati and tail-pipe-nzzle utlet ttal temperature (fig. 4). As sma13 amunts f water are injected, th tail-pipe temperature decreases because f the increase in cycle efficiency and the pssible increase in cmpressr efficiency. The discussin

9 MCA EM N. E7C12 f the effect f water injectin n the engine cmpnents, which shws that the turbine and cmbustin efficiency are apparently unaffected, indicates that the increase in tail-pipe temperature at the higher water-air ratis is prbably caused by a decrease in cmpressr efficiency. SUMMARY OF RESULTS Results frm an investigatin in the Cleveland altitude wind tunnel f thrust augmentatin by injecting water at the inlet f the axial-flw cmpressr f a turbjet engine with a fixed-area 3 tail-pipe nzzle 16 inches in diameter at an inlet-air temperature 8 f apprximately 520 R are as fllws: 1. Water injectin in the cmpressr inlet affrded limited gains in thrust accmpanied by large increases in specific liquid cnsumptin. With a tail-pipe temperature f 1680 R and at a simulated flight Mach number f 0.265, the net thrust was increased 15 percent at a pressure altitude f 5000 feet and a water-air rati f and 12 percent at a pressure altitude f 20,000 feet and a water-air rati f These thrust increases were based n the thrust available frm a standard turbjet engine at a simulated flight Mach number f and pressure altitudes f 5000 and 20,000 feet with an inlet-air temperature f 520 R. The respective specific liquid cnsumptins under these cnditins were 220 and 280 percent greater than the specific fuel cnsumptin withut water injectin. 2. Injectin f water resulted in large changes in the cmpressr-utlet temperature and pressure distributins, which were prbably accmpanied by a reductin in cmpressr efficiency. 3. In rder t maintain limiting tail-pipe temperature and thereby btain the mwiitmmt available thrust at all water-air ratis, a variable-area tail-pipe nzzle shuld be used.

10 NACA EM W. E7C12 4. At flight cnditins at vhich the inlet air must he heated t avid icing during the prcess f water injectin, thrust augmentatin "by the use f water injectin is nt practical. Flight Prpulsin Eesearcb labratry, Natinal Advisry Cmmittee fr Aernautics, Cleveland, Ohi.

11 NACA EM N. E7C12 APPENDIX - CALCULATIONS Symbls The fllwing symbls are used in this reprt: A crss-sectinal area, sq ft B C-. thrust scale reading, lb external drag cefficient f installatin (determined frm pwer-ff tests) c_ specific heat f gas at cnstant pressure, Btu/lb/ F F* jet thrust, lb F n net thrust, lb g acceleratin f gravity, ft/sec 2 h enthalpy, Btu/lb J mechanical equivalent f heat, ft-lb/btu P ttal pressure, lb/sq ft abslute p static pressure, lb/sq ft abslute q dynamic pressure, lb/sq ft E gas cnstant, ft-lb/lb E S wing-sectin area, sq ft T ttal temperature, E T^ indicated temperature, B. t Btatic temperature, E Y velcity, ft/sec W a air flw, lb/sec

12 10 HACA EM üb. E7C12 Mf fuel cnsumptin, lb/hr W gas flw, lb/sec Wj liquid cnsumptin, lb/hr Wit -water cnsumptin, lb/hr Wf/F n specific fuel cnsumptin "based n nt thrust, lb/hr/lb thrust Vj/F n specific liquid cnsumptin "based n net thrust, (lb f fuel + vater)/hr/lb thrust f/a fuel-air rati PI/PQ ram-pressure rati w/a vater-air rati 7 rati f specific heats fr gases 04 pressure crrectin factr, P4/2H6 (turbine-inlet ttal pressure divided by KA.CA standard sea-level pressure) r\ efficiency, percent 64 temperature crrectin factr, 74T4/I.40 x 519 (prduct f 7 and ttal temperature at turbine inlet divided by prduct f 7 and ttal temperature fr air at HACA standard sealevel cnditins) p mass density f gas, slugs/cu ft Subscripts: a air b cmbustin. g gas m mixture f steam and gas r inlet duct at survey rake, statin r t turbine

13 HACA EM Kb. E7C12 11 v water x inlet duct at slip Jint, statin z 0 tunnel test-sectin free-air stream 1 cwl inlet 5 cmpressr utlet 4 turbine Inlet 5 turbine utlet 6 tail-pipe-nzzle utlet Methds f Calculatin Temperature. - A cld calibratin f a sample thermcuple up t a Mach number f abut 0.8 shwed that the thermcuple measured the static temperature plus apprximately 85 percent f the adiabatic temperature rise win^ t the impact f the air n the thermcuple. Static temperature may be determined frm indicated temperature by applying this factr t the adiabatic relatin between temperature and pressure in the fllwing manner: t = (I) 2=1 7-1 CD and the ttal temperature 2=2, 7 T = < ) 2= LCD 2=k 7-1 (2)

14 12 NACA EM N. S7C12 Air flw. - The air flw thrugh the engine was determined frm pressure and temperature measurements btained with a vertical survey rake installed in the inlet duct 11» feet ahead f the engine inlet. Air flv was calculated "by * p Ay k \2J30 v (3) The static temperature in equatin (3) was btained by use f equatin (1). Jet thrust. - Jet thrust was determined frm the balance-scale measurements by cmbining the frces n the installatin in the fllwing equatin: a T x Fj = B + CJ^JS A x (p x - p 0 ) (4) The secnd term in the right-hand side f equatin (4) represents the external drag f the installatin and the third and furth terms cmbined represent the frce n the installatin at the frlctinless slip jint in the inlet-air duct. Equivalent airspeed. - Inasmuch as all calculatins are based n 100-percent ram recvery, the equivalent airspeed crrespnding t the ram-pressure rati at the engine Inlet can be expressed by 2J e p *i,i 2=1 (5) Because the adiabatic temperature rise due t the cwl-inlet velcity was lw, the equivalent free-stream ttal temperature can be assumed equal t the cwl-inlet indicated temperature. The use f this assumptin intrduces an errr in airspeed f less than 1 percent.* Nt thrust. - When the equivalent free-stream mmentum f the Inlet air is subtracted frm the jet thrust, the fllwing equatin fr net thrust is btained:

15 NACA KM N. E7C12 13»» -»j - T 2 < 6 > Cmbustin efficiency. - Cmbustin efficiency was calculated by making a thermal heat balance f the entire engine. The enthalpy at the cmpressr inlet included the enthalpy f the dry air upstream f the engine and f the water injected. The enthalpy at the tailpipe-nzzle utlet included the enthalpy f the burned gas and f the superheated steam. These values are cmbined in the fllwing equatin, which expresses cmbustin efficiency as b _ V8 *w t h «.6 *«" Vl V * * Vl 5[ C7 ) 18,600 Vf Methd f integratin. - Cmpressr-utlet temperatures and pressures were averaged with respect t the radial mass-flw distributin. Temperature and pressure prfiles (figs. 16 and 17) were used t calculate the mass flw thrugh six incremental annuli at the cmpressr utlet. Each incremental mass flw was then divided by the ttal mass flw t btain the integrating factrs. Each incremental value f temperature and pressure was multiplied by the crrespnding mass-flw integrating factr. The sum f these prducts was used as the average ralue. REFERENCES 1. Fleming,. A., and Dietz, R. 0.: Altitude-Wind-Tunnel Investigatins f Thrust Augmentatin f a Turbjet Engine. I - Perfrmance with Tail-Pipe Burning. NACA EM N. E6I20, Lundin, Bruce T., Dwman, Barry V., and Gabriel, David S.: Experimental Investigatin f Thrust Augmentatin f a Turbjet Engine at Zer Earn by Means f Tail-Pipe Burning. NACA EM N. E6J21, 1S46.

16 NACA RM NO. E7 C I 2 Fi gs. 1,2 Cmp ress n. Engine inlet Ai r man! fl d at er mani fl d inlet duct ccessry dme Figure I. - installatin f wate r-i n j ec t I n manifld ahead f cmpressr infet. NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS at er i r j et -Tj&mV^V:-. Figure 2. - Crss-sectin f al r-atmi zing spray nzzle used fr water injectin.

17 T) W Statin 6, tall-pipenztle utlet Statin tarbine atlet c Statin %, ' turbine inlet Statin 3, caaressr atlet NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS Statin I, COMI inlet Statin 2, cmpressr (nlet > Figure 3. - Crss sectin f turbjet engine shwing statins at which instrumentatin & was Icated. > m K)

18 NACA RM NO. E7CI2 Fig. 4a NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS l 5600 Turbine-utlet temperature, 1680 R 3400 \ X / O »»f «I ft» 4>» St si < "> r' ,.i * Water-air rati, w/a (a) Pressure altitude, 5000 feet, rr»t>-stream static pressure, p 0, 1757 punds per square ft» Figure 4. Effect f water injectin n tail-pipe-nzzle utlet pressure and temperature f turbjet engine. Engine speed, 7600 rpmj equivalent flight Mach, number, 0*265} inlet-air temperature, apprximately 520 R.

19 Fig. 4b NACA RM N. E7CI2 r TöS.04 Water-air rati, w/a (b) Pressure altitude, 80,000 feet} free-stream static pressure, p Q, 972 punds per square ft. Figure 4.- Cncluded. Effect f water injectin n tail-plpe-nzsle utlet ttal pressure and temperature f turbjet engine. Engine speed, 7600 rpm; equivalent flight Kan number, 0.265; inlet-air temperature, apprximately 520 H.

20 NACA RM NO. E7C12 Fi9 7\ 5700 NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS / f / /(> irbin«-utlet temperature, 1680 R S «/ 3400 «& ^ < > -V b 3300 (a) Pressure altitude, 5000 feet Water-air rati, w/a (b) Pressure altitude, 20,000 feet. Figure 5.- Effect f water injectin n jet thrust f turbjet engine. Engine speed, 7600 rpm: equivalent flight Mach number, 0.265; inlet-air temperature, apprximately 520 R«

21 Fig. 6 NACA RM N. E7C NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS f I a Ti rbine-utlet temperature, 1580 R a? 4* l n S /* y y (a 1 l Prei isure altil :ude ( 5000 feet» p / / 1800 / 1700 / A r \ \ 1600 ^^. c Water-air rati, w/a (b) Pressure altitude, 80,000 feet. Figure 6.- Effect f water injectin n net thrust f turbjet engine. Engine speed, 7600 rpai equivalent flight Mach number, 0*265} inlet-air temperature, apprximately 580 R.

22 NACA RM NO., E7CI2 Fig..VJ 15 NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS Y B 0. (a) Pressure altitude, 5000 feet. r «u - Turbine-utlet temperature, 1680 R «c S 85 s M BO / / / / OS.04 Water-air rati,»/a (b) Pressure altitude, 20,000 feet. Figure 7,- Increase In net thrust f turbjet engine btained with water injectin. Engine speed, 7600 rpmj equivalent flight Mach number, 0.865} Islet-air temperature, apprximately 820 B.

23 Ftg. 8 NACA RM N. E7 C! 2 NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS «a Turbine-utlet temperature, 1680 R 4400 P /"> ft' 3200 (a) Pressure altitude, 6000 feet ; / h < I Si < i.1 k.e 12.c S.c»4 Water-air rati, v/a.c)5.c >6.c >7 (b) Pressare altitude, 20,000 feet* Figure 8 # - Bffeet f water lnjetln n engine fuel nsumptln f turbjet engine. Engine speed, 7600 rpmj equivalent flight Maeh number, 0.265; lnlet-elr temperature, apprximately 820 R.

24 NACA RM NO. E7 C I 2 Fi gs. 9, 10 \ I 65 NATIONAL ADVISORY COMMtTTEE FOR AERONAUTICS 1 C 60 i (a) Pressure altitude, 5000 feet. l l-o f 1 Turbine-utlet tessera ture, 1680 R < 35 O C O Ci Water-air rati, w/a (b) Pressure altitude, 20,000 feet. Figure 9.- Effect f water injectin n air flw f turbjet.engine. Engine speed, 7600 rpv; equivalent flight Mach number, 0.265; inletair temperature, apprximately 520 R. VÜU TQ a u 016 Vn (a) Pressure altitude, 5000 feet. "* <> Water air rati, w/a (b) Pressure altitude, 20,000 feet. Figure 10.- Effect f water injectin n fuel-air rati f turbjet engine. Engine speed, 7600 rpm; equivalent flight Kach number, 0.265J inlet-air temperature, apprximately 520 R.

25 Fig NACA RM N. E7 C I 2 x r 4.0 j ^ 1.i^ ~ 5.0 y ^ O Specific fuel cnsumptin, y *fa n *» ' m D Specific liquid cnsumptin, *»/*n I Turbine-utlet temperature, 1680 R a. > r4 1 i S 1.0 / ^ n S* T - e * «S.O fi & 4,0 1 4* c e»4 3 s. i Pressure altitude, 5000 feet. / i""' NATIONAL ADVISORY C0J*HTTEE FOR AERONAUTICS 1 I 1 / ( ) 1 i r* 1 * 1.0 «4 «4 8. B 0 < ) Water-air rati, w/a (b) Pressure altitude, 20,000 feet. Figure 11.- Effect f water injectin n specific fuel cnsumptin and specific liquid cnsumptin f turbjet engine. Engine speed, 7600 rpmj equivalent flight Wach number, 0.865; inlet-air temperature, apprximately 520 R.

26 NACA RM NO. E7CI2 Fi gs. I 2, I 3 \ 1 4» e 1» 3 l, M 8. NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS (a) Pressure altitude, 5000 feet. I 100 ( ) O C O C Water-air rati, v/a (b) Pressure altitude, 20,000 feet. Figure 12,- Effect f water Injectin n cmbustin efficiency f turbjet engine. «4 4» m u I 9 m 4» 4» SI «4 i Pressure altitude (ft) O 5,000 20, / 1 A / t / f *t perc mt) 7B ""s )» ) SI I 3< t W..J57 Jfi^..., Crrected gas flw, - % a i»» lb/s e 4 T 4 { R 8 Figure 13. Relatin between crrected gas flw and turbine ttal-pressure rati with water Injectin. Turbine-characteristic efficiency cnturs Obtained frn previus investigatin. 1

27 Fig. 14a NACA RM N. E7CI2 I I 7600 vsna COMMITTEE FOR AERONAUTICS Static pressure, p 3 Turbine utlet temperature, lefs 0 R I T a i 4» 1 J. O 01 a I * * * -' * V 1 M»"^ 1 "" 1 «? S 900 s v 5 Ä 4* 9 O I a «u X X 'v <* 1 t fiflol.ff "".0 s Water-air rati, w/a (a) Pressure altitude, 5000 feet. Figure 14.- Effect f water Injectin n cmpressr-utlet ttal pressure, static pressure, and ttal temperature. Engine speed, 7600 rpmj equivalent flight nach number, 0,266; Inlet-air temperature, apprximately 620 R. '

28 NACA RM NO. E7 C 1 2 (4b NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS $ 3 t-i «1 & m 4600 s jfcal pressure, Pg fcatlc pressure, p_ lrbine utlet temperature, 1680 R a- a 3 a t> e «-( s ^" I _ --- ^^* ^ y y y y s y y n u % S* *» 4.^ 800 v I N V \» I 3 U *> O «w U 5 K p e- e a I 4 * ^- ^^ ~^" - -»^ _ 600 i.()1.()2.(».()4.< c Water air rati, /«(b) Pressure altitude, 20,000 feet. Figure 14.- Cncluded. Effect f water Injectin n cmpressr-utlet ttal pressure, static pressure, and ttal temperature. Engine speed, 7600 rpra; equivalent flight Mach number, 0.265; inlet-air temperature, apprximately Oc 0 tv»>

29 Fig. 15 NACA RM N. E7CI2 NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS 4,4 Turbine-utlet temperature, 1680 R \^ (a) Pressure altitude, 5000 feet Water-air rati, w/a (b) Pressure altitude, 20,000 feet Figure 15.- Effect f water injectin n cmpressr ttal-pressure rati. Engine speed, 7600 rpm; equivalent flight Mach number, 0.265; inlet-air temperature, apprximately 520 R,

30 NACA RM NO. E7CI2 Fig. 16B NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS Water-air *»a*ie V.UJ.04 ßk ~ «OS s m «4> O 43 4» V H 43 s a t» fioo 500 **= ; "9-- ^< ^ \l > d *^ ** **, c -. _ \ »^ \ s v 's, '^ \ u 400 In wa ner i,,0 Ou wa ft* Radial distance acrss cmpressr-utlet annulus, in. (a) Pressure altitude, 5000 feet. Figure l6.- Effect f water injectin n cmpressr-utlet ttal-teaperature distributin. Engine speed, 76OO rpa; equivalent flight Mach number, O.265» inlet-air temperature, apprximately 520 R.

31 Fig. 16b NACA RM N. E7CI2 NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS Water-air rati F ** 800 0) h 3 t 700 <Kc ^; ^x 43 O *» *» 4» 3 U O w 4» u & r 76 T76 Outer wall Radial distance aer«* capressr-utlet annulas, in. (b) Pressure altitude, 20,000 feet. Figure l6.- Cncluded. Iffeet f water injectin n cmpressrutlet ttal-temperature distributin. Bngine speed, 7^00 rpa; equivalent flight Mach number, O.2655 inlet-air temperature, apprximately 520 B.

32 E7CI2 NATfONAL ADVISORY COKMITTEE FOR AERONAUTfCS 7a OS 7000 Inner wall 2 Outer wall Radial distance acrss cmpressr-utlet annulus, in. (a) Pressure altitude, 5000 feet. Figure 17*- Affect f water injectin n cmpressr-utlet ttal- and static-pressure distributins. Engine speed, 7600 rpm; equivalent flight Mach number, O.265* inlet-sir temperature, apprximately 520 R.

33 Fig. 17b NACA RM N. E7 C I NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS -«J fl) at U3 m <a c u p. 3 O «9 v> V u % 3800 Inner Outer wall wall Badial distance acrss cmpressr-utlet annulus, in. (D) Pressure altitude, 20,000 feet. Figure 17»- Cncluded. Effect f water injectin n cmpressrutlet ttal- and static-pressure distributins. Engine speed, 76OO rpm; equivalent flight Mach number, O.265; inlet-air temperature, apprximately 520 R.

34 NACA RM NO. E7CI2 Fta f 8a NATIONAL AOVISORY COMMITTEE FOR AERONAUTICS Water-air rati in tä? 43 «H rh 43 4> rh 43 s E u in I f // / / Inner wall s / / / / / / : / / 1 '/ t >*""" s '-. "^ ^"^ _^--»- \ X Outer wall Radial distance acrss cmpressr-utlet annulus, in. (a) Pressure altitude, 5000 feet. Figure 13.- Effect f water injetin n cmpressr-utlet velcity distributin. Engine speed, 7^00 rpm; equivalent flight Mach number, 0.205? inlet-air temperature, apprximately 520 E.

35 Fi I 8b NACA RM N. E7C \1 -A Inner wall Radial distance acrss cmpressr-utlet annulus, in. (b) Pressure altitude, 20,000 feet. Figure Cncluded. Effect f water injectin n cmpressr-utlet velcity distributin. Engine speed, 7600 rpmj equivalent flight Mach number, 0.265; inlet-air temperature, apprximately 520 R.

36 4 >> I ATI Diet«, Rbert 0. DIVISION: Pwer Plants, Jet and Turbine (5) OBIG. AGENCY NUMBER Fleming, Wn. A. SECTION: Perfrmance (16) CROSS REFERENCES:Engines, Turb-jet - Perfrmance data RM-E7C12 (34155); Engines - Perfrmance bsting (32874); REVISION AUTHOR(S) Thrust augmentatin (94090) 'g AMER. TITIE: Altitude-wind-tunnel investigatin f thrust augmentatin f a turbjet II - Perfrmance with water injectin at cmpressr inlet ORIGINATING AGENCY: Natinal Advisry Cmmittee fr Aernautics, Washingtn, D. C. TRANSLATION: COUNTRY D.S. LANGUAGE FORG'N.CLASS u - S.C1ASS. Eng. DATE PAGES May'47 33 ILLUS. 18 FEATURES graphs, drwgs ABSTRACT Wind-tunnel tests were cnducted n thrust augmentatin by injecting water at the inlet f the axial-flw cmpressr f a turbjet engine with a fixed-area tail-pipe nzzle 16 3/8 in. in diameter at an inlet-air temperature f 520 R. With a tail-pipe temperature f 1680OR and at a simulated flight Mach number f 0.265, the net thrust was Increased 15> at a pressure altitude f 5000 ft and a water-air rati f and 12$ at a pressure altitude f 20,000 ft and a water-air rati f Specific fuel cnsumptin was 22 and 28$ greater, respectively, with water Injectin. NOTE: Requests fr cpies f this reprt must be addressed t N.A.C.A., Washingtn, D. C. T-2. HQ.. AIR MATERIEL COMMAND AlR TECHNICAL INDEX WRIGHT FIELD, OHIO. USAAF Wf-O-Jl MAI 47 «M*

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