*SECURITY INFORMATION

cc),, 222RM E53103

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RESEARCH MEMORANDUM

EFFECT OF INLET-AIR TEMPERATURE ON PERFORMANCE

OF A 16-INCH RAM-JET COMBUSTOR

By A. J. Cervenka, E. E. Dangle, and Robert Friedman

Lewis Flight Propulsion LaboratoryCleveland, Ohio

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NATIONAL ADVISORY COMMITTEEFOR AERONAUTICS

WASHINGTONC)ctober29,1953

— ——

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NACA RM E53103

NATIONAL ADVISORY COMMIT’I!FXFOR AERONAUTICS

RESEARCH MEMORANDUM

EFFECT!OF INLET-AIR ‘I!EMF’EMI’UN3ON FZRFOF+MNCE OF A

16-INCH RAM-JET COMBUSTOR

By A. J. Cervenka, E. E. Dangle, and Robert Friedman

suMMARY

The effect of inlet-air temperature on the conibustionefficiencyof a 16-inch ram-jet engine was determined in a connected-pipe installat-ion. The engine was operated over a range of fuel-air ratio withseveral dtiferent caibustor configurations and two fuel types.

Couibustionefficiency was found to be as much as 35 percentagepoints lower at an inlet-air temperature of 160° F than at 600° F. Thevariation in efficiency was a function of fuel-air ratio and combustordesign. With flame-holder designs in which the local fuel-air ratio wasmaintained near stoichiometric in the burning zone, or at over-allratios near stoichiometric, the temperature effect was slight. When thelocal fuel-air ratio varied appreciably from stoichiometric, a greatereffect was found. These findings are in accordance with previousobservations, discussed in a survey of literature, in which the effectof temperature was shbwn to diminish a-tthe regions of high ctiustionefficiency.

The performance of a sloping-baffle flame holder at an inlet-airtemperature of 160° F tith gasoline fuel was about the same as wZthMTL-F-5624A grade JP-4 fuel at 600° F over a range of fuel-air ratiofrom O.020 to 0.062.

IN’IRODUC!L’ION

This investigation is part of a ram-jet ccmbustor design programbeing conducted at the NACA Lewis laboratory. The objective of this

program is the attainment of conibustordesign and design criteria thatwill permit stable and efficient ram-jet cotiustion over tide ranges offuel-air ratio and combustor-inlet conditions.

The initial phases of this program reported in references 1 to 4were conducted at a simulated flight Mach nwiber of 2.9 and at a corre-sponding inlet-air temperature of 6000 F. At this test contition, whichis tithin the range of interest for long-range missile application,conibustordesigns were evolved that gave couibustionefficiencies of 90~ercent or greater over a fuel-air ratio range from 0.010 to 0.060.

2 NACA RM E53103

There is, nevertheless, considerable interest in ram-jet applicat-ions at lower flight Mach numbers and at correspondingly lower inlet-alr temperatures. Therefore, an investigationwas undertaken to estab-lish the quantitative effect of inlet-air temperature upon the perform-ance of selected ram-~et ccmibustordesigns. The inlet-air temperaturesinvestigated ranged from 160° to 600° F. Additional variables wereintroduced by the use of several conibustorconfigurations and two fueltypes.

Previous pertinent analfiical and experimental work on the effectof inlet-air temperature on ram-jet coubustor performance was reviewed,and the findings are discussed in relation to the experimental datapresented herein.

Ac

AF

E

e

H

SYMBOLS

The following synibolsare used in this report:

Kl,~,etc.

N

n

Pi

Pr

P.

R

Ti

Tr

combustor maximum cross-sectional area, sq ft

flame front area, sq ft

activation energy, Btu/lb

base of natural logarithms

minimum spark-ignition energy, Btu

constants

fuel evaporatedstream from a

constant

conibustor-inlet

static pressure

static pressure

for gasoline-type fuel injected contra-siqple orifice-type nozzle, percent

static pressure, lb/sq ft abs

at beginning of reaction, lb/sq ft abs

at point of ignttion, lb/sq ft abs

specific gas constant, Btu/lb/%?

combustor-inletabsolute temp=ature, %

absolute temperature at beginning of reaction, .‘R

.

.

—.

NACA RME53103 3

‘o

b

%

v=

x

absolute temperature at point of ignition, ‘R

fundamental flame velocity at standard conditions, usually 298° K,ftjsec

flame velocity at conibustor-inletconditions, ft/sec

inlet mixture velocity based upon maximun cross-sectional area ofconibustor,ft/sec

conibustor-inletvelocity, ft/sec

fraction of original fuel-air m&dmre that reacts in a givenperiod of time

combustion efficiency, percent

iqpulse efficiency, percent

density of unburned gases, lb/cu ft

functional notation

THEORETICAL BACKGROUND

The effect of inlet-air temperature upon the cuibustion process ina jet engine can be examined theoretically if a simplified model of theprocess is assumed. The actual conibustionprocess consists of successivesteps of vaporization of the fuel, mixing of fuel and air, and oxidationof the fuel-air mixture. Thus, a shuplified couibustionmodel canbe setup by the assumption that one of these steps is sufficiently slow withrespect to the others, so that the slow step would control the over-alJ_combustion rate and hence govern the combustion efficiency. For exsmple,in a model where vaporization is controlling, the over-all rate of com-bustion wouldbe determinedly the rate of evaporation of fuel. Forthis case, the influence of inlet temperature and other conditions uponevaporation rate is reported hy reference 5 as the equation

(4

Ti4.4 vi0.80

N100-N = ‘1 10 ~ 1.2 (1)

4A

Equation (1) shows the strong dependence of degree of evaporation upontemperature and the lesser influence of inlet pressure and velocity.

4 &mTIIDENimA.h NACA W E53103

For a mixing-rate-controllingmodel, the effect of inlet temperature 9

is not usually expressed explicitly; instead, a Reynolds number corre-lation is employed. In reference 6 a nearly linear relation betweenReynolds number and eddy diffusivity, a mixing-rate parameter, is

.

reported in the range of Reynolds number of interes~ in the ram-jezfield. In the burning zone, flame area is also a function of Reynoldsnuniber(ref. 7).

The assumption of an oxidation-rate-controllingmechanism for theconibustionprocess allows the use of several methods of expressingtemperature relations. These methods involve the use of such parametersas minimum spark-ignition energies, flame speeds, and reactant concen-trations. The effect of temperature and pressure upon minimum sparkignition is reported in reference 8. The data of reference 8 have beenplotted and found to fit the equation

..

(2)

The relation between temperature and a flame-speed parameter Is shown inreference 9 to follow the form

w = K3 + K4T: (3)

The effect of temperature upon chemical reaction is givenby thewell-known Arrhenius equation. A specific form of this equation,derived for application to conibustorstudies, is shown in reference 10

% (4)

EXFZRIMNTALBACXGROUND

The characterizing quantities discussed in the preceding paragraphshave all been suggested for possible use in conibustion-efficiencycor-relations. Vaporization-controllingmechanisms have not been employedsuccessfully in this respect, although measurements of the effect offuel vaporization upon efficiency have been reportedby many sources,such as references 2, 11, and I-2. The experience of these investigatorshas been that vaporization rate is not controlling under the usual con-ditions of ram-jet-engine combustor operation.

For combustion mechanisms that assume oxidation-rate controls,several correlations of conibustionefficiency have been proposed, each

NACA RM E53103 ~- 5

being derived from one of the temperature-dependent parameters given inequations (2) to (4). himum spark-ignition energy is used in refer-ence 13 to correlate efficiency of a turbojet conibustor. The data arepresented in the form of a plot of ~ as a function of P~/H where

~ is cmibustion efficien~y, pi is conibustorinlet static pressure,and H is miniumm spark-ignition energy. An approximate formla may bewritten for the linear portion of the curve up to efficiencies of about80 percent. This formula, with the temperature stistitution for Hfrom equation (2), is

(5)

Another correlation employing minimwn spark-ignition energy is given byreference 14 in which impulse efficiency rather than combustion effi-ciency is employed as the performance criterion. A linear portion ofthe plot presented in reference 14 with temperature substituted forignition energy from equation (2) maybe representedby the relation

(6)

In references 7 and 15, a combination of mixing- and oxidation-controlling mechanisms is utilized. Combustion efficiency ~ isdefined in terms of flame area (a mixing parameter) and flame speed (anoxidation parameter)

%’”%% = puAcVc

(7)

The flame area AF was evaluated as a function of velocity> pressure,and temperature; and the flame speed ~ was e~ressed as a function oft~erature. From these substitutions and experimental measurementsupon vaporized stoichiometric fuel-air mixtmres in a 5-inch ran-jetcotiustor, a correlation of combustion efficiency is established in theform

1.1up:”%t UF

%— = 7.0 V:08n

(8)

This correlation holds w to efficiencies of 80 percent, above which thedependence of ~ upon the pressure-temperature-velocityparameterdecreases sharply. The flame-speed factor allows equation (8) to beapplied to different fuel types, exceptions being certain fuels such as

. .carbon disulfide whose low ignition ener~ apparently causes combustionsteps other than oxidation to be controlling (ref. 15)0

-—— —

6 NACA RM E53103

The reaction-rate quantity given in equation (4) forms the basis ofan efficiency correlation proposed in reference 10. In this correlation,conibustionefficiency is defined in terms of the fraction of the totalfuel consumed in the reaction time allowedby the inlet velocity andconibustorle th.

7

The final correlation is given in the form of a func-tion of PiTi Vi, with turbojet performance data correlated according to

the equation

(9)

c

v

—

NJ

om

In this correlation the decreased effect of the inlet conditions uponcombustion efficiency where the efficiency is greater than 80 or 85 per-cent is also noted. At efficiencies greater than 85 percent, the slopeof the correlating curve is very gradual.

While of considerable interest, these combustion-efficiencycorre-lations are not in themselves sufficient for prediction of efficienciesof actual ram-jet-engine combustors. The actual combustion process is farmore complicated than indicated in tliemodels set up for the correla-tions, and rarely can an actual combustor performance be identified as .

corresponding to these simplified concepts. Nevertheless, these corre-lations do serve a very useful purpose in indicating trends in the effectof inlet conditions and suitable ranges of operation with respect to high

.

efficiency.

The most helpful experimental investigations for the purpose ofcombining experimental and analytical correlations of the effect of inletvariables, specifically temperature, upon caibustion efficiency are thosein which these variables in the test burners are studied independently.Early ram-jet work in this respect is that of reference 16, where theeffect of inlet temperature, pressure, velocity, and cmibustion-chaiberlength upon combustion efficiency was studied in an 8-inch ram-jet com-bustor. The work presents plots confirming the hypotheses that the ‘combustion efficiency is improved by increased temperature, pressure,combustor length, and by decreased inlet-air velocity.

The correlations of both references 7 and 10 indicate that conibus-tion efficiency below values of 80 percent increases linearly withabsolute inlet-air temperature.

—In reference 17, the effect of inlet-

air temperature is shown for investigations carried out with both 5-inch—

and 20-inch co?ibustorsemploying V-gutter and can-type flame holders.Data for homogeneous, prevaporized fuel injection show a linear effectof inlet temperature upon combustion efficiency. Data obtained withlocal liquid injection into the 20-inch V-gutter conibustor,on the other .

hand, fail to obey a linear relation, presumably because evaporation rategoverns the efficiency in this case. Other investigations of interestinclude those of reference 18 for a 20-inch ram jet, reference 12 for a

.

NACA RM E53103 7

.

I?

.

.

2-inch burner, and reference 19 for a 10-inch quarter-segment can. Thesestudies show that the effect of temperature is felt most strongly atfuel-air ratios where the efficiency is low; thus, increasing inlettemperature broadens the range of fuel-air ratio at which high combus-tion efficiencies are obtained.

From the experience of these previous investigations, it maybeconcluded that if the combustor is operating at high efficiency nearthe caibination of inlet conditions where the temperature effect becomesappreciable, a decrease in operating temperature will cause a markeddrop in cotiustion efficiency. In contrast, if the conibustoris oper-ating at nearly the same high efficiency, but well above the criticalvalue of inlet variables, a decrease in operating temperature will notaffect the conibustionefficiency.

KPPARATUS

The 16-inch ram-jet engine and test installation for this investi-gation, shown in figure 1, were the same as described in reference 1.

Flame holders. - The two flame-holder configurations used were thesloping baffle and can shown in figures 2(a) and 2(b). Design detailsof these flame holders are given in references 3 and 4. The ratio ofthe cold-flow total-pressure drop across the flame holder to the dynamicpressure upstream of the flame holder was 1.5 for the can and 2.0 forthe sloping baffle.

Fuel injectors. - The same fuel injectors were used with thesloping-baffle flame holder (configurationA, fig. 2(a)) and tith thecan-type configurations in which upstream injection was used (configu-rations andC, figs. 2(b) and 2(c)). Amixbme-control sleeve wasused for configurations A and C to maintain a locally rich zone beforethe flame holders (ref. 1). The six primary spray nozzles, located sothat the fuel spray would enter the control sleeve, were rated at 0.5gallon per minute at a pressure differential of 100 pounds per squareinch. The 16 nozzles that supplied.secondary fuel, located so as tospray into the annulus outside of the control sleeve, were rated at 0.36gallon per minute at the same pressure differential. Details of thenozzle arrangement used with the internal fuel-injection system in con-figuration are given in figure 2(d).

Fuel. - The properties of the two fuels, MIL-F-5624A grade JP-4 andclear~oline, are given in table I..

.

8 WNF33JEN’MAJ!P NAcA m E53103

PROCEDURE

Operating conditions. - The ram-jet couibustorwas operated at theair mass flows, range of inlet pressure, and range of inlet velocitynoted for the following inlet~air temperatures:

Inlet-air temperature, %? 600 480 300 160

Air mass flow, lb~sec 14.5 18 20.5 25Inlet-air velocity, ft/sec 230-260 200-260 170-260 165-260Inlet-air pressure, in. Hg abs 36-32 46-33 50-33 54-33

.

*

—.

The inlet air was preheatedby a gas-fired heat exchanger and wasthus supplied to the test unit uncontaminated.

Combustion efficiency. - Combustion efficiencies were determinedlya heat-balance system. Combustion efficiency is defined as the ratio ofthe enthalpy change of fuel, air, quench water, and engine cooling waterto the heating value of the fuel input. At a given engine operatingcondition, the quench-water flow was adjusted to a value insuring quench-ing of the combustion products and complete vaporization of the water..

.

Mixture temperatures of 6000 to 900° F were maintained at the thermo-couple station. Negligible heat loss from the ducting downstream of the .water spray was assumed.

RESULTS AND

Sloping Baffle -

The conibustorperformance datafhme holder (configurationA) over

DISCUSSION

Configuration A

obtained with the sloping-bafflea range of inlet-air temperature

from 160° to 600° F-and with two fuels ar~ shown in figure 3~a). Effi-ciencies of 90 percent or greater were obtained at all temperaturesinvestigated in the fuel-air range from 0.030 to 0.062. Since inlet-airpressure and velocity varied appreciably with fuel-air ratio at the low

.

inlet-temperature conditions, the effect of temperature on combustionefficiency is not clearly shown near stoichiometric caditions.

—.—In the

fuel-air ratio range from 0.010 to 0.030, the effect of temperature becamkmore pronounced, since the inlet conditions of pressure and velocity weremore severe than at higher fuel-air ratios.

At a fuel-air ratio of 0.0155, combustion efficiency decreased from93 to 60 percent when the air temperature was decreased from 600° to1600 F. This is almost a linear dependence of combustion efficiency with -inlet absolute temperature. Thus, it appears that while the conditirmsof the runs above a fuel-air ratio of 0.030 are such that the inlet temper- ,ature has little effect upon efficiency, the inlet pressure and velocityat fuel-air ratios below 0.030 are sufficiently stringent to produce the@eater temperature effect cited in references 7, 10, and 15.

~Emq

NACA RM E53103 9

wo

G

.

At the 160° F inlet conditions, a rich stable burning limit wasencountered at a fuel-air ratio of 0.034 with JT-4 fuel. No limits were

* found with gasoline. A possible explanation for the rich limit was theimpingement and collection of liquid fuel on the control sleeve andother surfaces upstream of the burning zone, resulting in an unfavorablevapor fuel-ati mixture downstream of the baffle tith the less volatilefuel. Cmibustion efficiencies with gasoline fuel at 160° F were approx-imately the same as with JP-4 at the 600° F condition over the fuel-airratio range from 0.020 to 0.062.

Can-Type Conibustor- Configuration B

In figure 3(b) is shown the effect of inlet-air temperature on theperformance of a can-type cotiustor with upstream fuel injection (con-figuration B). The trend.in conibustionefficiency with inlet-air tem-

y perature was similar to the trend found with configuration. At rich

g mixtures no significant temperature effect was found, whereas at leanfuel-air ratios efficiency increased considerably with increasing inlet-

. air temperature (20 percentage points at a fuel-air ratio of 0.025).

Stability limits were also improved with increased temperature.. Lean blow-out occurred at a fuel-air ratio of 0.009 at 160° F, whereas

no lhits were found at 600° F.

Can-Type Conibustor- Configuration C

The performance data obtained with the can-type flame holder, dualUpstream injection, and control sleeve (configuration C) are shown infigure 3(c). Co&mstion efficiencies were 92 percent or greater at aninlet-air temperature of 600° F with proper selection of primary- andsecondsry-fuel flows. At lower temperatures, the efficiencies rangedfrom 80 to 90 percent, except for a limited region in the lean and richfuel-air ratio ranges where values greater than 90 percent were obtained.A fuel-air ratio of approximately 0.025 apparently represents a stoi-chiometric mixture in the primary zone. At this fuel-air ratio and atan over-all fuel-air ratio near stoichiometric, very little temperatureeffect was found.

.

.

The effects of primary fuel-air ratio and fuel type with this con-figuration are shown in figure 4. These data indicate that in thetransition region between primary alone and cotiined primary and sec-ondary fuel injection (0.025 to 0.035) a primary fuel-air ratio of0.025 gives best results for JP-4 fuel. For richer operation, the pri-mary fuel-air ratio shouldbe reduced to 0.014. A slight improvementwith gasoline over JP-4 fuel was noted in the rich region.

10 (mYmmNTW NACA RM E53103

.

Can-Type Combustor - Configuration D

The effect of inlet-air temperature on the performance of a can-type conibustorwith internal fuel injection is shuwn in figure 5. Withthis configuration, co?ibustionefficiency was high at lean and low atrich mixtures for all the inlet temperature conditions investigated.At a fuel-air ratio of 0.020, a temperature increase from 160° to 600° Fresulted in a cotiustion efficiency increase from 87 to 96 percent. Thesame temperature variation at richer conditions resulted in efficiencyincreases of 15 to 20 percentage points.

The effects of primary fuel flow and fuel t~e are shown in fig-ure 6. Except for a slight advantage with primary fuel in~ection onlyat a fuel-air ratio of 0.020, no effects of primary fuel flow or fueltype were observed.

From the results of these tests, it appears that the effect ofinlet-air temperature upon cofiustion efficiency is slight for flame-holder designs in which the local fuel-air ratio is maintained nearstoichiometric in the burning zone, even though the over-all fuel-airratio varied. On the other hand, with conibustorsin which the localfuel-air ratio varied appreciably from stoichiometric, either rich orlean, the effect of inlet temperature was more pronounced and approachedthe magnitude predictedby the correlations of references 7 and 10.Thus, It is seen that the favorable stoichiometric conditions correspondto the regions of small temperature effects, and the more severe off-stoichiometric conditions correspond to the regions of greater tempera-ture effect.

SUMMARY OF RXSULTS

The following results were obtained from an investigation of a 16-inch ram-jet engine with both can-type and sloping-baffle flame holdersin a connected-pipe installation:

1. Conibustionefficiency was found to be 0 to 35 percent lower atan inlet-air temperature of 160° F than at 600° F. The variation inefficiency levels was a function of fuel-air ratio and combustor design.

.

MotP(J—

4

.

—

2. With conibustordesigns employing fuel injection upstream of theflame holder, the most pronounced effect of inlet-air temperature wasfound at lean fuel-air ratios; however, with internal injection theeffect was greatest at rich fuel-air ratios. The region where the inlet-air temperature showed the greatest effect corresponded to the region of

.

severe operating conditions, lean fuel-air ratios for upstream injection-.

and rich fuel-air ratios for internal insectio~ d

NACA RME53103 11

.3. The use of a fuel-air mixing-control sleeve was found to be more

beneficial at low inlet-air temperatures than at high temperatures withthe can-type flame holder..

4. ‘Theperformance of the sloping-baffle flame holder at an inlet-air temperature of 160° F with gasoline fuel was about the same as at600° F with JP-4 fuel over a fuel-air ratio range

wo!+ Lewis Flight Propulsion @boratoryw National Advisory Committee for Aeronautics

Cleveland, Ohio, August 31, 1953

~REFERENCES

21. Cervenka, A. J., and Dangle, E. E.: Effect of

Z on Performance of a 16-Inch Ran-Jet Engine.

from O.020 to 0.062.

Fuel-Air DistributionNACARME52D08, 1952.

2. Dsagle, E. E., Cervenka, A. J.j and Bahr, D. W.: Effects of Fuel-. Temperature and Fuel Distribution on the CcmibustionEfficiency of

a 16-tich Rsm-Jet Engine at a Simulated Flight Mach Nuniberof 2.9.NACARME52J14, 1953.

.

3. Cervenka, A. J., Bahr, D. W., and Dangle, E. E.: The Effect of Fuel-Air Ratio Concentration in Caibustion Zone on ConibustionPerformanceof a 16-Inch Ram-Jet Engine. NACARME53B19, 1953.

4. Cervenka, A. J., Perchonok, Eugene, and Dangle, E. E.: Effect ofFuel Injector Location and Mixture Control on Performance of a 16-Inch Ram-Jet Can-Type Conibustor. NACA RME53F15, 1953.

5. Bahr, D. W.: Evaporation and Spreading of Iso-Octane Sprays in HighVelocity Air Streams. NACA R14E53114

6. Towle, W. L., and Sherwood, T. K.: Eddy Diffusion - Mass Transfer inthe Central Portion of a Turbulent Air Stream. Ind. andEng. Chem.jvol. 31, no. 4, Apr. 1939, pp. 457-462.

7. Reynolds, Thaine W., and Ingebo, Robert D.: Combustion Efficiency ofHomogeneous Fuel-Air Mixtures in a 5-Inch Ram-Jet-Type Conbustor.NACARME52123, 1952.

8. Fennj J. B.: Lean Inflammability Limit and Minimum Spark Ignition. Energy. Ind. andEng. Chem., vol. 43, no. 12, Dec..1951, pp.

2865-2869.

.

12 JiUXIFZBENT~ NACA RM E53103

9. Dugger, Gordon L.: Effect of Initial Mixture Temperature on Flsme .

Speed of Methane-Air, Propane-Air, and Ethylene-Air Mixtures. NACARep. 1061, 1952. (SupersedesNACATN’S 2170 and 2374.) .---

10. Childs, J. Howard: Preliminary Correlation of Efficiency of AircraftGas-Turbine Combustors for Different Operating Conditions. NACARME50F15, 1950.

11. Longwell, J. P., Van Sweringen, R. A., Jr.} Weiss, M. A.} and HattJF. G.: Preparation of Air-Fuel Mixtures for Ramjet Conibustors. ;Bumblebee Rep. No. 168, Esso Labs., Standard Oil Dev. Co., Nov.1951. (ContractNOrd 9233 with Bur. Oral.,U. S. Navy.)

12. Mullen, James W., 11, Fenn, John B., and Garmon, Roland C.: Burnersfor Supersonic Ram-Jets: Factors Controlling Over-all BurnerPerformance. Ind. andEng. Chem., vol. 43, no. 1, Jan. 1951, pp.195-211.

13. Graves, Charles C.: Effect of Oxygen Concentration of the InletOxygen-NitrogenMixture on the ConibustionEfficiency of a SingleJ33 Turbojet Combustor. NACA RME52F13, 1952.

14. Calcote, H. F., Fenn, J. B., and Mullen, J. W.) II.: Correlation ofClassical CcmibustionQuntities tith met B~ner perfor~nce”Bumblebee Rep. No. 130, Experiment Inc., May 1950. (ContractNOrd 9756 with Bur. Oral.,U. S. Navy.)

15. Reynolds, Thaine W.: Effect of Fuels ori-ConibustionEfficiency of5-Inch Ram-Jet-Type Cotiustor. NACA RM E53C20, 1953.

16. Cervenka, A. J., and Miller, R. C.: Effect of Inlet-Air Parameterson Combustion Limit and Flame Length in 8-Inch-DiameterRam-JetConibustionChauiber. NACARME8C09, 1948.

17. Bennet, W. J., and Maloney, J.: Altitude Tests of the Convair 20-Inch Diameter Can Type Comibustor. Rep. No. ZM-9136-010,Consolidated-VulteeAircraft Corp., San Diego (Calif.), my 1950.

18. Beam, Thomas T.: Results of Direct-ConnectedAltitude Proof Testsof the XRJ-43-MA-1 Model C20-2.5A6 Test Ramjet at the W-P APB,May 12-June 22,tion, Marquardt

19. McFarland, H. W.:Rep. 8-2, Univ.Navy Bur. Aero.

1950. Memo. Rep. No. M-1207, Ram.jetDesign Sec-Aircraft Co., Dec. 5, “1950.

Development of Supersonic R-jet Buners~ USCALSouthern Calif., Aero; Lab, Feb. 19, 1951. (Us. .-Contract NOa(s)9961, Item 2.)

.

.—

NACA RM E53103

●

✎

13

.

.

TABLE 1. - SPECIFICATIONS AJIDANALYSIS OF PRIMARY ENGINE FUELS

MIL-F-5624A GRADE JP-4 AND CLEAR GASOLINE

A.S.T.M. distillationD 86-46, %Initial boiling pointPercentage evaporated

51020

3040

5060708090

Final boiling pointResidue, percentLoss, percent

Specific gravityReid vapor pressure,m/sq in.

3ydrogen-carbonratioJet heat of conibustion,3tu/lb

Specifications,M1’L-F-5624A

E

250 (~X. )

550 (max.)1.5 (max.)1.5 (max.)

’47 (min.),0.826 (max.,0 (min.), 3.0 (max.)

18,400 (min.)

140

1992242502702903053253523844274871.20

0.7652.7

0.16918,70Q

110

137X541782002182352502652843053581.31.4

0.7166.7

0.18218,925

.

.

t!!idi, l,,ln-1,,,,

u

,

m /

rCdOMnwter I l—)

41

d-t-(!II

L- Waler A

L DMfusm L Cmlbwtknl/ 111!

~Mllmer

burner /= caneDk?fua.r

a

I

I

,

~ ~“ ~1Figure 1. - Jhtal.htlon of 16-lnoh ram+.t engine.

CD-3167

. ,

, 3043” , ,t

Seccrdary fuel

injeotorIWrhme-contml sleeve

7 i

PMmary fuel

Injectors r ~!.jopingbai?flee

(a)

mgure 2. -

[ L ~Pilot Midng shield

Conf@ratlon A

Ccxnbustm mmlfiguratione.

!5

I I

(b) Confi~tlm B.

F@re 2,m-3L19

- Con-blnuerl. Colllhwtmcomp*atim .

1 r , CY-3 3043 , ,

T16 SemndEW u@mam Injeotcrrs

.5” \ *I.x prlnurry upstream Irdeatam

I—.

(’o)Configuration C.m-3120

Figure 2. - Continued. CcnIdusto.rtWJf@lI’dEiOIIB .

l----”+I Seoomlfmy injeotcm

7- 1

Frim3ry nozzle

=-M-%o

~on

A A

D o

A A

00

Seccmdary mule

I?ozzls

W=-YI

Mozzle rating&oticm at MO lb/q in.,

&i%lIl

o Cmicalc1 Cmdcd~ Cmoncal

-- ~mmlfold

Er#~_0.667 1.QOO

& Doundmeenl

Drmnstmelil .625 .625

@==u3-tI 1

(a] cmfllgumtion D.*

mgure 2. - Clmrhaea. Cdxmtor CsOnrigmationEi.

, WOG ‘ ‘

1

Inlet-ah temperature, Fuel

OF—

o m JP-4

4-75 JP-4

—: 300 JP-4A 160 J-P-4

v 160 Clear gasoltie

— Open symbols - prhmry fuel wilysolid symboh - primary plus seconds

7fuels (pr*ry fuel-8tiratio, 0.02

I I I I I I I I p=97

Figure 3. - Ccahstor

al-r temperatures.

.02 .03 .04

Fuel-air ratio

(a) Configuration A..

performance of configurations A,

.05 .06, .07

B, anclC over a range of inlet-

Pm

. --

. .

Mm

1~>

. -●

● m

c

60 /

0

-. / TEo - I

/

I

1 Inlet-air teqerature,

40I

OF

oI

mA 160

I Open synibole - primry fuel only

ISolid aymbola - prinmryplua

m secuudery fuels (primary fuel-r ah ratio, 0.02)

I

I I

IJfBlowout

I

o .01 .02 .03 .04 .05 .06

Fuel-air ratio

(b) Configuration B; J_P-4 fuel.

Figure 3. - Continued. Combuetor performance of conflgmatiom A, B, endC over a range 0S inlet-air temperatures.

Woc ‘ ‘

NACARME53103

●

21

100

80

60

Inlet-air temperature,OF

w 600n 4750 mo

—~— 160 BOpen symbols - primary fuel onlySolid symbols - primary plus

secondary fuels (pr~ry fuel-airratio, 0.025)

/❑ m ● A W4 L

Ac

AA ●m m ■

+ // +

a, ‘A ●A* _s,?!!~ “

40

A +

.01 .02 .03 .04 .05 .06

Fuel-alr ratio

(c) Configuration C!;JP-4 fuel.

Figure 3. - Concluded. Conibustorperformance of configurationsA, B, and C over a range of inlet-air temperatures.

22 NACA RME53103

.

100

80

60

Fuel Injector Primary fuel-air ratio

o JT-4 Primary only -----JP-4 Primary plus secondary 0.014

: JP-4 Primary plus secondary .02A m-4 Primary plus secondary .025v Clear gasoline Primary plus secondary .02

v

c> # A+

5~r- \

c) d 1

6 >v

sK9

r

c ❑

w

1-

—.01 ●O2 .03 .04 .05 .06

Fuel-air ratio

Figure 4. - Effect of primary fuel flow and fuel type on—

combustion with configuration C. Inlet-air temperature,160° F; velocity, 165 to 260 feet per second; pressure,54 to 33 inches of mercury absolute.

.

.

, . ,

I 1 I I I 1 1 I 1 I I I

I I I IInlet-air temperature,

‘% I I

.01 .02 .03 .04 .05 .06 .07

Fuel-ah ratio

5043,

E?

Figure 5. - Combustor performance of configuration over a range of hlet-

air temperatures. JP-4 fuel. N

24 NACA RM E53103

1 I 1 I I I I I 1

Fuel Injector Primary fuel-air ratio

Io J3?-4 Primary only -----

❑ W-4 Primsry plus secondary 0.0140 n-4 Primary plus secondary .02

100 A Clear gasollne Primary only -----

v Clear gasoline Primary plus secondary .02 1

.01 .02 .03 .04 .05 .06

Fuel-air ratio

Figure 6. - Effect of primary fuel flow and fuel type oncombustion with configuration D. Inlet-air temperature,160° F; velocity, 165 to 260 feet per second; pressure,54 to 33 inches of mercury absolute.

NAcA-Lm21eY-n-29-53- 325