NATIONAL ADVISORY COMMITTEE"FOR AERONAUTICS

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APR 161946-- \0; .

TECHNICAL NOTE'

No. 1037

i_. t

A STUDY OF COMBUSTION IN A FLOWING GAS

By Mitchell Gilbert, Gordon Haddookand Allen Mettler

..Aircrart Engine Research Laboratory

Clevelanii, Ohio__.. -._ -_.:r-~- .... - ... _ -.:.~

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NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS

TECHNICAL NOTE NO. 1057

A STUDY OF COMBUSTION IN A FLOWING GAS

By Mitchell Gilbert, Gordon Haddockand Allen Metzler

SUMMARY

The results of a prelim~nary study or combustion in rlowinggases are given and apparatus ror obtaining high rates or heatrelease per unit volume of combustion space is described. The prin-cipal feature of the combustion apparatus is an electrical element(Globar) mounted concentrically within a stainless-steel pipe. Theannular space between the inner and outer elements serves as thecombusti0n space.

Tests were made over a wide range of fuel-air rati0s, inle~mixture velocities, and electrical heat inputs, using propane gasas the fuel. The effect of these variables on the extent of com-bustion and mixture in:flammab11ity was investigate.d.

The results obtained- with the combustion tube are as follows:

1. The greater the surface-volume ratio, or the_..B!'.eater theam0unt of heat addible to the gas ~tream, the greater the inlet-mixture velocity at which appreciable compustion can be obtained.•

2. For a given fuel-air ratio, tho total rate of heat output(Btu/sec), equal to the sum of the electrical and chemical energyreleased, increases with increasing velocIty. However, bo~h theextent of combustion: as measured by the combustion factor ~,and the total heat output (Btu/lb of fuel) decr&ase·with increaseof velocity for most of the fuel-air ratios tested.

3. The most inflammable mixtures, as determined by the lengthof heating element necessar~ to produce ignition,' are those ofapproximately stoichiometric proportions of ruel and air .

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INTRODUCTION

NACA TN RD. 1037

An investigation of some OfithO basic factors affecting com-bustion In a flowing gas stream was instltutmi in ordor to eupplya basis for future design and evaluation of Jet-propulsion pcwe~plant%. The tests wer~ made using a combuetlon tub~ that incor-porated an annular heating space in which-a fuel-air mixture wasburned findthe rosulttng energy release measured, This type ofapparatus waa eelected primarily because of its suitability andconvenience for the study of individual factors affecting cmnbus-ticm ani is not meant to be a suggested type oPJet-propulsionburner or its pratotyp~.

The data reported wero obtained as part of a survey perfozmmd%t the Cleveland laboratcmy of the NACA early in 1’344covering arange of operating variables including inlet-mixture velocit~es,heat additions, and fuel-air ratioa. ‘l?he purpose of the surveywas to c.btainqualitative knmrledge of the effects of these vari-ables or.cmbustion phenomena} as well as to discover the capabil-ities of the apparatus.

APPARATUS

The combustion tube”and the flow diagram are ehown in fig-ures 1 to 3. The combustion tube con~ists of a horizontal silicon-carbide electric heating element (Globar) placed concentricallywithin a stainless-steelpipe, thus forming a narrow annular epacewhose width iff0.06 and 0.12 inch, respectively, for the 5/8- andl/2-inch-dhuneterheating elements used. Through this space, ametered fuel-air mixture is passed. &cause of the high rate ofheat transfer obtained In such a small annulus, the mixture Is ,rapidly heated from room temperature to its ignition temperature,which causes combustion to t~e place in a confined, relativelyshorti-spaceof 15 inches or less. The completeness of combustioncan then be calculated from a heat balance for the cambuetion tube.

The air for the tests was supplied from a laboratory syskuunder a pressure of 100 pounds per square inch. The fuel was acommercial product containing a minimum of 99 p~rcc3ntpropme.The air md fnel flows were controlled by pressure-ragulatfngvalves and measured by orifices. Electrical pcwer was suppliedby a 14 kilovolt-ampere saturablo reactor-voltage regulator.

In order to make a heat balance Tor the combustion tube.,aswell as to obtain information pertinent to the combustion process,the following measurements were made:

.-

—.

.-.+. .

* ‘-

—

—

NACA TN No. 1037 3

,-

“9

(1)

(2)

(3)

(4)

(5)

Air and fuel flows

Inlet and efiaust temperatures

Tube and heating-elerientsurface temperatures

Electrical power input to the heating element

Pressure drop ecross the combustion tube

The maximum error of the individual measurements used for the calcu-lation of the heat balance was esttited to be less than +10 percent.Because estimations of the specific heat of the exhaust gases and anapproximation of the heat losses through conduction> convection andradiation introduced a considerable error, the uncertainty of anyresults shown in the present paper may be as high as+25 percent.

a

Cp

c1

De

%

%

AH

L

q

SYMBOLS

conihstion factor, dinensicmless

mean specific heat at constant pressure, Btu per pound per

dimensional constant

hydraulic diameter (D2 - ~), which is eq~al to four timeshydraulicr@ius, feet

diameter of Globar heater, feet

inside diameter of pipe, feet

net theoretical heat of reaction of propane, Btu per pound

heating length,required for ignition, feet .

rate of heat energy input cm output, Btu per second -

Subscripts referring to q,:

c energy liberated

e electrical power

by combustion

input

h increase of total energy in gas

the

air

.-

—

2 total energy loss. “

4

T&v

Ti

%8

ATa

A’Im

v

Wa

Wm

T-

.-.

NACA TN No. 1037

-.

Lnax theoretloalmaximum energy llberatud by combustion

prlmo (1) indicates air datum ruri”

weighted avij~agettiperatum of inside surfaces, ‘F

Inlet-mixture temperature, %

ignition tcmperatur.~”offucil-airmixturu, ‘F

lncreas~ in tumperatme” of thu air from Lnkt. to. exhaustc.mditj.ens,‘3?

Increase in twqwrature &fuel-air mixture from Uot to ~xhuustnconditions, %?

msximum inlet-Mtxtlm.eveloclty fur ignition, feet per second

weight flow of air, pounds per second

weight flaw of fuel-air mixture, pounds per second

JHJ?ERIMEITIMLPROCEDURE AND CALCULATIONS

In order to determine the effect on combustion”of the additionof heat from hot surfaces, the inlet-mixture,velocity, and,thefuel-air ratio, about 500 runs were made “bovorl~ the followi~dranges:

Inlet-mixtura voluoity~ f%et per second . . . . . . . . . . 0-200Power input, or heat addition, kilow~t”ts. . . . . , j . . 0.50-6Fuel-alrratio. . . . . . . . . . . . . . . , . . . . , . o-~,oo

Illustrative data have been selected for presentation in this report.For thu data presented, the absolute pressure varied between 1 end

1$ a~spheras and tho inlet-mixtur~t=perature was 80° F. Thc3

pressure dro~ across the tube during cmnbustion wae generally lessthan 15 inches of weter.

The fuel-air mixture was admitted to the tu~e,’ignited byi.ncreas:lngthe electrical power input, and burned. When stableconditions of combustion were obtained, pertinent”pressures, tem-poraturos, and powers were recorded, The fl~u-front~ositlon wasestimated from the abrupt change in tcmporature alo~” the outertube surface that xcurred during combustion. Physioal limitations

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I?ACATN Nti.1037 5

of the apparatus with regard to maximum allowable temperaturescaused gaps in the d8ta. The maximum observed Globar temperaturewas about 2900° F.

A combustion factor was used as a measure of the extent of .

combustion. The combustion factor ‘a is defined as the ratio ofthe actual rate of heat liberated by combustion to the theoreticalmaximum rate of heat liberated by combustion based on the standardnet heat of combustion of propane.

The actual rate of heat-energy liberated q was obtained bya simple heat balance for the combustion tube. The heat balanceincluded (1) the electrical power input ~, (2) the rate ofincrease in heat content of the gaseous mixture qhj (3) Wecombustion-tube rates of heat loss through radtation, conduction,and convection qz, and (4) the rate of combustion-energyrelease qcc

The heat balance for a combustion run can thonbe expressed by

&=qh+qz-qe (i)

where qz is obtained frcanthe dat% for’air-datuq runs at.a similartemperature level and distribution as for the combustion run.

For theheat-balance

,,

The value of

air-datum runs, in which no fuel was introduced, theequation is

q’. = q’h +q’z

q’2 is determined by the difference between the

(2)

measured value of q’e and the calculated VdUe Of q’hj where

q’h is equal to WaCpATa. The values of. q’z aro dtitermin@dfora range ofconditims by making air-datum runs for a range of tem-peratures and temperature distributions of th~ combustion-tube .outer surface.

For simplification of the calculation of qhj the reactionwas assumed to take ”placeat the inlet-mixture temperature withthe resulting products being heated to the final temperature [raf-erence 1, p. 2G4). Tho rate of increase in heat content can thGnbe calculated from

.

qh = ‘mcp*Tm (3)

6

Thotho fuel

. . . NACA TNNo. 1037

qmax = Ama (4)

where 6H is a function of fuel-air ratio for lean mixtures andcmstant’for rich mixtures. The combustion factor a i& thencaJ.culat@ from the relation’ ,“

(5)

.,. RESULTS

Tne Effljctof Heat Addition on Maximum Inlet Velocity

Hel~ttransfer from the heabing elomegt to the inlet-mixturestream :rapidl.yraises its temperat~~e to “theigniticn point, thntIs? to the paint at which oxidation reactions will become apprecl.-able. It i.sevident that the more heat which can be added to themixture per unit time the higher the mixture velocity at whichignition and combust~on will occur wl,thina given length of chamber.An examhation of figure 4 shows tbt the maxidum permissibleinlet-mixture velocity is a function of thahoat addition for thetwo sizes of Glohar heater under oonsi3eratim.

.The maximum permissible inletmixture velocity may bo assumed

to correspond t(.)the minimum tern’eraturerise required f{.:rignitionto occur in a length equal t!>that of the combustion tube. Ingeneral, the temperature rise isia function of the mixture velocity!the power input, and th~ hydraulic radius of the amulue (refer-ence 2, pp. 1.97-202). In this reference, the heat-transfer rate forturbulent,-flowCmndj,iions h tubes and”annuli is shown 113increaseapproximately with tho 0.8 power of the velocity, whereas the-time

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of contact of the gas with the hea~ing element ~b decreased in dlroctpraport..onto velocity increase”. The pradictod tomperatum rise ofthe stream will therefore Vai-yInversely with thu 0.2 pcwur of theVoloclt:r. Furthermore,,the heat-tr.ansfw rate varies almost invorscl~with tho hyiraulic diamwter De, The igrlitirmtemperature for con- “stant inlet density would”then be expected tu fol;lowtho equation(derive?lIn the appmd ix) .-—. “.

NACATN lb. 1037

.

m“

Equation (6) predicts, for a given ignition tempc3ratUreandheated length, a greater mQximum inlet velocity for a smallerhydraulic radius, OZ*larger Globar size. The trend of the data offigure 4 agrees with this prediction. It should be noted thatfor a given power input the values of Tav will not be the samein the two cumuli considered. For the larger Globar (smallerannulus) Tav will be smaller for two reasons: (1) for the sameradiative power loss (same electrical power), the radiation perunit area of surface is mnaller for the larger Globar, and (2) theconvective heat transfer per unit temperature difference betweengas and surface is greater at a given velocity. A given amount ofelectrical power Is therefore dissipated from the larger Globar ata lower surface temperature. Curves of constant Tav superimposedon figure 4 would thus have a greater positive slope than the curvespresented. The expertients were not run under conditions thatisolate the ignition temperature while holding all variables but”-“’–one constant. For the range of velocities and electrical powerinputs in the experiments, the ignition temperatures varied between550° to 700° F.

The Effect of Fuel-Air Ratio and Velowity on

Combustion Factor and Heat Output

Figure 5, which is representative of the test data, shows therelation between fuel-air ratio, velocity, and ocmibustionfactor a.The dotted portions indicate that an abrupt decrease to zero in aoccurs with decrease In fuel-air ratio at fuel-~ir ratios in the

.-.

region of 0.02. Th6 data in the very lean region is meager butseems characterized; as far as has been observed, by a falling offin combustion factor from a very high value to anegligible valuein a narrow range of fuel-air ratios. ,Suchan abrupt drop in “awould be caused by a coniiustiblelimit but was not found in therich range of mixture ratios ttjsted;”The ralue of u raaohos amaxtium at about 0.02 in figure 5 and decrfiasesas the fuel-ati ”-”

....—..—.

ratio is,increas~d; however, other data obtained in the investi-gation indicate that the maximumvalues of a occur in a regionbetween 0.02 and 0.06. The most rapid decrease in a in the rich-mixture range occurs between fuel-air ratios of 0.10 and 0.14, afterwhich the drop is quite gradual. For the expertiental conditionsinvestigated velocity increases prduce a sensible decrease in ‘aonly in the rich region.

The effect of fuel-air ratio and velocity on the total rateof heat output is illustrated in figure 6. The total rate of heatoutput refers to the sum of qh + qz or its equivalent qe + qco

-. .—

... ..

8 NACA TN Na. 1037●

It is a useful index of the total heat generated by the unit-andclearly illustrates the maximum output for fuel-air ratios near *stoichiometric, the maximum being of the order of 17 Btu per secondat 150 ~eet per second and 3.8 Btu per second electrical p~werinput. The trend is similar for all power inputs encountered.

Fi,gure7 is a plot based on the total heat release per poundc]ffuel and reflects the marked effect of the decrease of a withincreasing fuel-air ratio, as well as the effect on u of increas-ing the velocity. The difference in appearance between the cutivesof figures 6 and 7 at lean mixtures is due to decreasing fuel flowin the ordinate variable of figure 7 with decreasing fuel--airratio. —

Th@ quantity of heat-released in Btu per hour per cubic footof combustion volume per standard atmosphere was computed frcm thedata plotted in figures 6 and 7, The volume of the annular spacowith the l/2-inch Globar is 0.0025 cubic foot, For a prtissum of1 atmosphere} tho heat liberated by combustion varius b&woen1 X106 and 19 X 106 Btu/(hr)(ft3)(atm), whccreasthe heat rdeaseof the Globar approximates 5 x 106 Btu/(hr)(ft3) atm). Hmco,

ithe total rate of heat output varied from 6 X 10 to24 X 10~3Btu/(hr)(ft3)(atm), M comparison, a c~~o~tj.o~ljet-propulsionburner releases bet.woun2 x ld6 @ .$

6 X 106Btu/(hr)(ft3)(ati)~ The rate of combustion-energy releageper uni-:volumo for the combustion tubo can thus be several timeskrgor ‘;hanfor a jot-propulsionburner. It should also bo notedthat thijhuat-release values for the combustion tube wuro based

..

on the ‘;otalannular volume althuugh cumbustlon occurred in onlyapproximately 50 percent of the total volume.

MIXTURE IJEUMMABZLITY

The inflammability of a gas mixture may be described in variouawaya. Nlame speed maybe the useful criterion of inflammability ifthe rate at which a mixture can be burned is of intere~t. The rela-tive eaoe with which gas mixtures can be ignited by sparks, hot spots,pilot flames, or other energy sources may also be taken as a measureof inflammability. The ignition temperature, or the temperature atwhioh self’-propagatingreactions begin is -other inflamnmbilitycrlterim. A Tourth Is the range of.mixture proportions of fuel,‘oxidant,and diluent than can be ignited by a ‘standardenergy sourceand that are capable of self-propagation of flame.

It has been recognized in the literature that the data usedas a mee,sureof the inflammability of a gas mixture dopond on thechoice clfthe criterion of inflammability and that inflammability

NACA TN No. 1037 9

is a function of the intrinsic properties of the mixture and theproperties of the confining system. The data of previous investi-gators (references’3, 4, and 5) have indicated that gas mixturesof stoichio?netricproportions or with .aslight exbess of fuel aremost inflammable with respect to the aforementioned oriteria ofinflaumlability.

In the combustion tube, mixture inflammability is associatedwith the flame-front pzmition, which is the upstream boundary ofthe burning zone. The farther upstream in the tube the flame frontwill stabilize for a given inlet velocity, or the lower its ignitiontwnperaturti,the more inflammable is the mixture. Relating inflam-mability to the flame-front position appears to be a more satisfac-tory procedure for the conibustiontube than relating inflammabilityto the combustion factor a because a involves the burning ratesafter ignition has occurred and these rates are difficult to deter-mine at present. Also, the effects of any ignition lag the mixturemay possess is included in the measurement of flame-front position.

The data obtained with the combustion tube (fig. 8) are inagreement with the results on inflammability given in the litera-ture. Figure 8 shows qualitatively the effect of fuel-air ratioand velocity on flame-front position. In agreement with the the-oretical reasoning which suggested equation (6), it is also foundthat an increase of electrical power moves theflame front fartherupetresm.

SUMMN3Y OF RESULTS

1_% a study of the combustion of flowing gas in a combustiontube, the following results were obtained:

1. The greater the surface-volume ratio, or the greater theamount of heat addible to the gas stream, the greater the inlet-mixture velocity at whioh appreciable ccunbustioncan be obtained.

2. For a given fuel-air ratio, the total rate of heat output(Btu/see), equal to the swnof the electrical and chemioal energyreleased, increases with increasing velocity. However, both theextent of combustion, as measured by the combustion factor a,and the total h08t output (Btu/lb of fuel) decrease with increaseof velocity for most of the fuel-air ratios tested.

-..-

10 NACA TN Na. 1037

Aircraft En@w Roswrch Laboratory,Natloual Advis:my Ci~ittdu for.A~’ronauti,ce,

Clevohn?l, Ohio, A;mil 1, 19461

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NACA TN Nao 1037

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s

APPENDIX - HEAT TRANSFER TO A FLUID FLOWING IN

T2

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m ANNuLus

T. I I T.+dT1 I

\ \\\\ \”\ ’J&’~uwax

If A is a cylindrical heatingture is T1 and B Is a concentricthe heat absorbed per unit time dqflowing with a mass velocity G is

where CD is the mean specific heat

element whoseO~ter wall atin a section

surface tempera-temperature TZ Jdx by fluid.

,. dq = ~ (D22 . D12] iiT

at constant preseure in

--

(7)

Btu/(lb)~°F).

. The heat absorbed byfrom the walls .inlength

dq = fiD2h2dx

the gas isdx.

(T2 -T) +

.-

equal.to the heat transferred1

fiD1hldx(Tl - T) (8). .

where Ill and h2 are heat-tramfer ocefficients in

Btu/(sec)(ft2)(°F). If the heat-transfer coefficients hl and h2are assumed to be equal, equation (8) becomes

Equate (7) and

a=

.

dq s fihdx[D2T2 + ~T1 - T(% - Dl)]

(9) and define

D1 D2 “and De= D2-Dl

D1 i-D2)b=Dl+,D2)

(9)

.-

-— -—

‘x=ww~,,-)Since G is conetant and If Cn, h, a, and b

asmxmd constant, equation (lO)’can be integratedx = 0: L and T = Ti, TO gl~i~

where

L length of

T~} To inlet and

combustion annulus, ft

NACA TN No. 10379

----●

—

( 10)

between the limits =-—

which may be shown

To -Ti=

L

to be equivalent to

1

.1[aTl + bT2 - T~ 1

For h there may be substitutedrelat~on of the form

and ah’> PV = G, Tav = a!Tl+“bT’2

whero

co dimensl.onlofjsconstant

(- ]-4hL-exp— cm GDa(roferance 2, p. 202) a

()

Cp Y ‘k—.

k Jlc)

P fluid ViSOOSit”y, lb tiss/(sec)(ft)

k t“hmmal conductivity, Btu/(soc)(f’t2)(’?I?/ft)

P fluid deneity, lb mass/cu ft

.-

- .-

(11)

—

—

... .--—_-

—..- -----

NACA TN No. 1037 13

v’”’ fluid v;locity’,‘ft/S6C

Tav weighted average temperature of inside surfaces, %

Then, if p, Cp, L, and k are assumed constant,”

To

[

(’ - CIL-Ti=(Tay-T~) I-ew(“ )]

“2-V l-v(12)

De ,V

where T~C!.8. Equation (12), ?resentd as equation (6) in thetext, gives Tig fw To for the caso where the outlet temparaturaTo corresponds to the ignition temperature of tha flti”d.

The assumption that bl = hz is questionable since recant data(references 6 and 7) show that the valuae for the inner and-outerwall coefficients are tifferant. Equation (12) is based on ‘~letconditions and thus neglects the variation of p, V, and h withtemperature. #ilso, Tav in equation (12) is a complox weightedaverage temperature in the case where T1 and T2 are na$ const~t

along the length of the annulus.

1. Hougen, O. A., and Watson, K. M.: Industrial @emical Calcula-tions. John Wiley & Sons, Inc., 2d ad., 1936.

2. McAdams, William E.: Heat Transmission. McGraw-Hill Book Co.,Inc., 2d cd., 1942.

3. Coward, H. l?.,and Jones, G. W.: Limits of Inflammability ofGases and Vapors. Bull. 2’79,Bur. ,Minas,1939.

4. Lewis: Bernard, and von El%e, Guenther: Stability and Structureof Burner Flames. Jour. Chem. I’hys.,vol. 11, no. 2,Feb. 1943, pp. 75-97.

5. Smith, Francis A., and Pickering, S. F.: Measurements of FlameVelocity by a Modified Burner Method. REM. Paper 900, Nat.Bur. Standards Jour. Ros., vol. 17, no. 1, July 1936, pp. 7-43.

14 NACA TN NO. 1037

6, Davis, 131merS,: ““HeatiTransferand Pressure Drop in Annuli.A.S.M.E, Trans., vol. 65, no. 7, Oct. 1943, pp. 755-759.

A.

—

*..=

7. McMillen, Elliott L., and Larson, Roger E.: Annular HeatTransfer Coefficients for Turbulent Flow. Trans. Am. Inst.Chem. ~., sec. A., vol. 40, no. 2, April 25, 1944,pF. 177-202.

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‘ACA TN No“ /037

*

NACA TN No. 1037 Fig. 2

Al B= , cl

*

.-*

Y

A.P--F+ .—

i Globar heater, low-resistance endB Hixture inletC Globar heater, middle, heating sectionD ExhaustE Thermocouple shieldsF Air ejectorG Thermocouple, Pt to Pt-10 percent Rh

NATIONAL ADVISORYCOMMITTEE FOR AERONAUTICS

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Figure 2. - Sectional v!ew of combustion tube and exhaustthermocouple.

.

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.: :.. .. . . i-- .. . .

Fig. 3 ; .’. , “,-”..”. ... :;;,..3:” +,. .=...... .

+

press ure-regutat ingWlues . . ... ...... .. ....T. b +--;....... .. . .. ..... . .. .~. .

L’”’”y”;r;i,;ce:%”’”’i”””’”’+“’-

x.””=l”l~”’””””“----,....—...

Throttle uo’fues,-. .. ..’... . . .

.. ‘“ ,,. . “...”-

Itixej ‘

Firecheck ““’% I

.,. - ... .>...... ..-, ., . ,.-.

-1..-...”.Mttmeter

Y

208 uolts a-c.

Ammeter

Insulotlngtransformer u

Voltoge regulatorII I

EJ. .: [ LSUrfuce thermocouples I,-. 1’I

.-?ombustion tube

. . . :. ““”1r+Exhoust thermocouple

“J...4

Aux!liarycombust iO/1

4*+ chamber

Compressed-oir jet....... .

....-..,.-,.. ... . .... .. . .....:+,:i ., ... . . , . ,.- ,+ ..;

“..”:”,cool., hg &ater” ‘“”-” -“””.. ... . ~1:< .; :. . ---- —-,.. .. .F---

,. ,..... .:.. rhrott,ie Uoll?e::.,, ..:

~~~ +.

. ..—

—

.

-L’ ‘ ‘‘ ‘“”’““”””-3...... ..-. ,,............. Cooling-

Exhaust goses to chimney uater trap.—. ~- ~. ...—.

-- ---—Y., “““”‘ ~ThrO’tte‘“’ve k. ~a.ter d.rein ,L ... . ...,! , . ., ---- -—. _,N—.“..i .-: .. .NA’fldhAi ‘iDVIS&Y .. _ .. . ... .+ —.. .—.“

COiWITTE~ FCI@.AERON~TIC~ :, -: ~::”. . . . .

Figure 3. - Floy.diogrornfor c0m6ust.i,on-~@e. q~P?~ot.~!:.:.. .+:..U ..~ .* . .?~~. . ..... .. ... . . . .... ... . . .- i: J=--—,.. - -.. .. ...--e-.

.- ----- -. ..--”_.1

*

-ix

zo.

0

0 1 3 4 5Eleotrloal&m input, klloiratta

Figure 4- - Effect of heat mldltlon on maxlmumpermiselble inlet-mixture velocity at which _l-l

ignition 1s obtained. Gas pressure, 1 to 1+ atmosphere. # Inlet temperature, gOo F; over- .m

all length of combustion tube, 19 inches;insidediameterof outer tube, 0.742 inch. *

. .

.

,,:, ,,,,

,, .,,-’.. ..” ..4

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NATIONAL AOVI SORVCOMMl TTEE FOR AERONAUTICS

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Fuel-sir mtio., ..,,.. ,; ngllre 5. - Effoot of fuel-alr ratio and inlet-mixturo velocity o! cornbuetlon factor. Electrical power input,.,Y:...- 3.6 to 4.2 kllontts (3.k to 4.0 BtU/ceC); WI Presmr@. 1 to,,.

> atm.pheres; inlet ternpemture, ?@ F; omr-

~;~ ,.t,.~,; i ●ll length of r.mbmtlon tube, 19 inches; inside dlaseter of outer tube, 0.74.? inch.,,, . ..J. J4:’!,:,, ,,Fi rl .;..; . i

. ,,,. ;, ,,,” . “.’.

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CADO CONTROL NO: j US CLASSIFICATION: 1 ATI NO:

1 Unclasso 1 S6cg OA NO:

TO-1037

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TITLE:

A Ttudy of Combustion In A Flowing Gas

f o C: < U e e a

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Abl AUTHOR(S): i, \ *

•Gilbert, P^itchell; HaddockJjiDbrdons Efetzler.Allen ORIGINATING AGENCY: J

"".tional Adviser:/ Corro$tj& Se Tor "eronai, ttic s FOREIGN TITLES: ,-~\ \

PUBLISHED BY: ~^°

Fame PUBLISHING NO: o Q <

TRANSLATED BY: TRANSLATION NO:

PREVIOUSLY CATALOGED AS:

CADO CONTROL NO: US CLASSIFICATION:

A Study of Combustion in A Flowing Gas

* AUTHOR(S):

I Gilbert, M0= HaddockB G „ ORIGINATING AGENCY:

^ National Adviso^f Corrroityfeg for Aeronautics

NO: _ I OA NO:

FOREIGN TITLES: T

PUBLISHED BY:

Same PUBLISHING NO:

TRANSLATED BY: TRANSLATION NO:

PREVIOUSLY CATALOGED AS: