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RESEARCH MEMORANDU~

ALTITUDE-TEST-C~ER INVESTIGATION OF PERFORMANCE

OF A 28-INCH RAM-JET ENGINE

II- EFFECTS OF GUTTER WIDTH AND BLOCKED AREA

ON’OPERATING RANGE AND COMBUSTION EFFICIENCY

By T. B. Shillito,W. L. Jones,and R. W. Kahn

Lewis FlightPropulsionLaboratoryCleveland,Ohio /“

i, ; ...,,.J.-.:

. . .

NATIONAL ADVISORY COMMITTEEFOR AERONAUTICS

WASHINGTONNovember 6, 19!50

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RM!IWAL ADVISORYOcMaTmE m AEEmwTIcs

RE6EARm~.

ALTITum—msT—~ mvEsTIG4TIoNa? ImRmwmE

OF A 28-R?CHRAM-JIM?-Iltll!

By T. B. SMllito, W. L: JoneEIand R*w. Kahn

h invest@atiauof the effechof flame-holderblookedaxea and@ter width an the perfcmmame of a 28-tnoh+iamter ram-$etengineat a almulated fllghtMoh numberof 2.0 and for altitudes&om40,000to 55,000feet has been oonduotedin a 10-fmt-diameteralti-tude ohmiber. The ten flameholdersinvestigatedincorporated60°annular-Vgutters,that variedin widthfrom 1.0 to 2.5 inohesendblookedfrom 40.5to 62.0peroentof the o&busticm-ohdbar area.All fhaueholderswere investigatedwith a fixed gecmetrioal arrange-

ment of the fuel-ln~eottonsystem,althoughoperationwith eitherone(auuularin:eotlon)or both (uniformQleotlon) of the two fuel-inseotionmeaifoldswas incltiedfor saneof the flameholders.

At a simulatedaltitudeof 50,000feet,lean limttsof ccmdxzs-tlon at a fuel-airratio of approSmately0.03were obtainedfcwannularInjeottonand approxlmatel.y0.04for unifomnlnjeoticm.Ths rloh limitsof owibustionwere greater than 0.065fuel-airratiofor the most stablemnflgurations. Corfibusttoneffiaienaiesfor these mnf@ratlons ringedfrom 0.7 to 1.0with uniformtijeo-tlon and from 0.4 to O.q for annularlnJeotlmh

Desirableoharaoteristiodof wide over=alloperathg fuel-air-ratiorangeand high mmbustloq +5’iqhnoy were most favorablywmbined in two flameholders. One.of theseflameholdershad2.O-lnoh-widewtters and a proseoted~ of 45.0 percentof theoanbusthn-chaiberwide guttersand achsmberarea.9

*

&mea and &-other flameholderkd 2.5-lnoh-projectedarea of 60 percentof the combustion-

...* h.,

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2 ~ “-” HACAR4 E5C!R21 “-”~ .

..-es ti guttm widthmom 1.0 to 2.5 inohesfor oonstant

blockedarea had no appreciableeffeota combustionefftolenoy -%~overa rangeoff’uel-airratiosfra 0.04!5to 0.065ad farmmbustlon-chamberpressuressllghtlylessthan oae atmosphere.Inoreaeingthe blockedarea of the flam holdersfrom 40.0to .--.,

62.0pbroentfor constantgutterwidths‘@’1.5 and 2.0 inches.=..

resultedin an increasein oonibustionefficiencyof 5 to 10 per-cent. The blow-outlimitsof the varioussatisfactorilycorrelatedchamber-inletMaohnumberThe degree”ofcorrelattcnpreviousinvestigators.

on the basisofto gutterwidthobtainedserved

lWMWIIUOTIOli

flameholderswerethe ratioof ccmbustion- ->,raisedto the 0,45power.to vertfy the work of ‘“

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An altitude-test-chamberinvestigationof the combustion-ohamberperformanceof a 28-inoh%xn-jetenginebeingdeveloped” a

by theMsrq-t AircraftCompanyhas beeg.-~oniuctedat the NACA’Lewislaboratory.Extensivedevelopmentaltestshave been oon-duotedby the enginemanufacturerat simulatedaltitudesup to

4,

approximately30,000feet ami for a simulatedflightMaoh numberof 2.0. The performanceInveatlgatlwat the Lewislaboratorycoveredthe rangeof simulatsdaltitudesfrcm 40,000to55,000feet at a simulatedflightMach number”of 2.0. ..

The purposeof the pro- describedhereinw?isto determinethe effeotsof the percmta~ of octmbustian-charnberflow areablockedby the proJeotedarea of the flameholderand af flame-holdergutterwidthon the mubustian perfeoe. Resultscd?anInvestigationof severalocmfigurationsin thisprogramare repartedin reference1. A seriesof 10 V-gutterf@me holderswere eval-uated. Theseflameholdk~ were designedto povide f’smilles&varyinggutterwidthwith approximatelycanstsntblockedarea sadVSWiIJ8blo~ed areawith approxiwtelyoonstantgutterwidth. Therunsweremadewith a fixedfuel-injeoticmsystemocmsistlngof twointernalfuel-msnifoldrhgs with spring-loadedfuel-spraynozzleslooatedapproximatelyone Conibustton-chemberMsmeter upstreamofthe flameholders. Rxr e?chflameholder,altitudeoperatkmallimits,combustioneffloiemy,and pressurelossesare givenandthe effeotsof blockedareaand gutterwidthon performanceemanalyzed.

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aB@i5mr’*

N(ICAm! E50H21

KemRA!rus

e The installaticmof the enginein the 10-footaltitudeohauiber% is desoribedin referenoe1. Featuresof the setuppertinentto

the presentinvestigationare repeatedherein.

Desorlptlm of elWlne. - A schematicdiagramof the engine issh&n in figure1. The enginemneisted primarilyof an outershelland an innerbody. The fowwardporticmeof the outershelland tunerbody formeden annum difYuserand the downstreampoationof the -outershellfomed the mxubustionohamberand the exitnozzle. Theflightengtiewith free-sham inletwas designedto produoea Maohnumberof 1.6 at the lip (sta.tian31) at a fllghtMach numberof 2.0.~ cwder to simulate this flow oonditiondur~ the altttude-test-ohambertivestigation,a bellmouihconvergent-divergentnozzlewasinstalledat the engineimletto acceleratethe atr frcunstagnationcomdltionein the altitudechamberto the requiredMach number. It

* was thus possibleto shulate the averageoonditloneof Maoh number,pressure,- t~ture that omur with the free-streaminletofthe fllghtocmflguratiaand to positionthe shookin the diffuser

h at the sameposlttonas in fllght. Beoauseexaotboundarylayer,Mach nuziber,and pressuregradients,and suboritioalspllloveroondt-ticmeof flightare not reproducedby this inletnozzle, the stabilityof the mibustim chamberand flightdiffuserocmibinatlcmoouldnotbe ti~stl~tedj -eOver, possibleeffectsof the inletboundaryX on velocityand pu?essuredletributionat the ocmilnzstion-ohaniberInletoouldnot be evaluated.I&au the 11P statim to the end of theinnerbody,the air-flw passagewas divergentwith the samedimen-sionsas the fllghtengine(referenoe1). The innerbody was om-neotedto the outershellby four longeroneexbendlngalmostthelengthof the innerbody.

The mnbuetbn dmiber Is 28 inohesin diameterand 46 Inoheslcmg. Attaohedto the omibustim-c@mber outletis a oonvergent-divergentetitnozzle19 incheslongwith a throatdiameterof20.75inchesand an outletdiameterof 22.44Inohes. The entireouter surfaoe of the cxxibudttonchamberand exitnozzlewas water-jaoketedto provideGooling. Fuelwas inJeotednear station197@ the flameholderswere mountedat statian239. Detaileddescriptionsof the fuel systemand the flameholdersare givensubsequently.

hetallationin altitudetest ohamber.- The Installationofthe engine& the 10-footaltitudetest ohamberis shownin fig-ure 2. 5 enginewas fittedwith a diaphragmsealat a forwardB baffleand a slldlngsealat a r- baffle. The frontbaffle

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4 3.-- N4clARM E60H21

providedan air-tightsealseparatingthe inletram-pressureatifrom the altitudeeihaust@ thuspermitteda pressuredifferenoeto be maintainedaorossthe engine. The rear bafflewall wasinstalledto keep the hot etiust gasesfrmu reolrcu.1.atlng aroundthe engine.

A suddenexpansionjetdiffuser(reference1)was Installedat the exit of the engine. This Jetdiffuserwas used to raisethe “highaltitudeoperatimallimitsiqposedby t~ laboratoryaltitude ,exhaustsystem.

Fuel-lnJeotionsystem.- The fuel system(fig.3) oonsistedoftwo manifoldseadhdividedIntofow quadrantslooatsdbetweenthelcmgeronsuppmtisand equippedwith s@ng-loaded nozzles. Adeaoriptimnof the fuelnozzlesis givenla referenoe1. The foursets, of eaahqenifold axe oonnectedoutsidethe ~lne to foatwo nmnlfoldrings. Twenty-fournozzleswere Installedin theouter (downstream)manifoldand 16 h the Inner (upstream)ma@fold.Fuel flowwas.individuallyregulatedto the two ma@folds. Runs inwhiohequalfuelpressurewae 8uppliedto bothmanifoldsare deelg-nateduniform-in~eothnrunsand thosein whiohfuelwas suppliedonlyto the innermanifoldare desimated annular-in.leotionruns.

%itod

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Th- fuelusedthroughoutthe investigaticm.IWIocuune%id grade “ ._.normalheptane. ,

Flameholders.- The 10 flameholdertiusedwere of similarmnstmuoticmand weremountedin the looationshownIn fIgures1and 3 (station239). Detaileddimensionsof the flameholdersareshownin figure4. The annulargutterswere armzged in a s-redV in the longitudinalplaneand were oonneotedand suppcwtedby

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radialguttersm plates. The ~lameholdersdifferedprincipallyin gutterwidth,numberand diameterof annulargutters,and pro-~ectedarea,hereinaftere~ressed as percentageof oombustlon-ohamberarea (28-inchdiameter)or percentageblockedarea. Thefollowingtableliststhe prtioipaldeeignfeaturesof the variousflameholders:

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0

.++:.;......

Fl&ueholder

123.45678910

Gutter

width(in.)

1.001.002.001.502.001.201.381.001.402.50

Blooked Lull=mulb??ofarea

(peroent)I rings

42.0 455.0 645*O 240.5 360.0 358.0 562.0 548.7 555.0 460.0 2“

Praotioaldlsposlticaof blockedarea preventeddes%gnof prectse“familiesbut the flameholdersmay be groupedin familieshavingnearlyoanstantgutterwidth or blookedarea.

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* e~le, flameholders5, 7, d 10 may be groupedto form a familyof varyinggutterwidthfrcm 1.38to 2.50 Imhes with CXC@a 2-peroentvarZEL-tion in blookedarea.

The flareoasesshownIn figure4 were IIwwUed for i&uiticKlduringflightbut were not used for s~lng duringtheseruns. Anlguitorbox similarIn prlnoipleto a m.lnlatureram Jetwas attaohedto the guttersto provideIgnitlcm.

I?uel-air-ratiometer.- The fuel-atw?atlodistributionwasmeasuredaheadof the flSmeholderby a oumneroiallyavailable.devioethat oolleoteda sampleof the mlxhzrein a l/8-lnoh4tametertubesimilarto a total-pressurethe ~ passedthe sampleover an eleo-trioallyheatedreslstanoeelament. Changesh ~t flow tlumughthe elementare msasuredwith ohangesin oompositlonof the gas.The Oument flow is proportionalto the thermalocslduotivltyof thegas,whloh Is propartlaualto the fuel-ak ratio. Canparlsonaf thesurveydatawith the fuel-alrratiomeasuredfrcm individualmetering6f fuel and air Indloatesthat the absoluteaoouraoyof the surveysis not adequatefor quantitativeoanoluskus. The trendsof thedistrlbuti~,however,are believedto be oorreotlygivenby theinstruuleult.

mst rumentatlm. - I’uelflowwas measuredwith a calibratedadjustableorifioemeter- alr flow was meaauredwtth a oanoentrio

M slm?p-edgeOrifioe. The engine-lnl.ettotal_rature and pressurewere measuredby rakBsat the bellmouthentranoe. The Ilumberend

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the looaticm of temperatureand statio-and total-presquremeasure-mentswithinthe engineare shuwnin figure1. The odbusttcm-damber-inlettotaland statlopressureswere measuredby a rakelooated”a few inchesupstreamof the flameholders. Water-oooledrakeswere usedto measuretotal‘pressurwat the ocmbustlon-chemberoutlet. St&lo pressuresIn the tist-nozzle threatwere measuredby fourwall statictubesand by eighttrailingstatiotubesmountedon streamlinedstrutsin the c?aubustionohsmiberand efiendlngdown-s-am to the nozzlet-at. The oombustian-dmmberand the exlt-nozzlecooling-waterflowand tezrpeixdmreriseweremeasuredin cinderto oaloulatethe heatremoved.

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PROCIEWHl —

The generalpmooedurefor most of the ironswas to i*fte theburnerat em Inletpressureof-approximately40 inohesof merouryabsoluteand an outletpressureof 25 Inchesof mercury,ccm-espondlngto a cabustlon-ohember-inletvelocityof approximately250 feet per

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seoond, with a fuel-alrratioof approximately0.04. When stableburningwas establi@md,the outletpressurewas slowlyreduoed .

untilohoklngomdltIonswere reachedin the exitnozzle. The englne-inletpressurewas then set to stmulatethe desiredflightconditions. . ‘

. With this pressureheld oomstant,the fuel flowwas variedh mallintervalsand dataware takenat stabilizedburningmnditlms untilrloh or lean caubustionblow-outocmrred. Ths ooastantinletpres-bureand inlettemperatureImposeduponthe ohokedInletnozzleresultedIn a mnstant alr flow throughthe enginefoirany givensimulatedaltitude. Runsweremade with t@ variousoonfiguratlmsat a simulatedflightMaoh nuniberof 2.0 and altitudesfrom 40,000to55,000feet.

The inlet-airtotalpressureat the lip statbn was mmputedfor the flightenginefor a rangeof altltudesat a fllghtMaohnumberof 2.0 from Oonioalshookrelations. The ~ssure at thebellmouthInletin the enginewas then set at the cczuputedvaluesfor eaohaltitude. This procedurenegleotsany lossin totalpres-surebetweenthe bellmouthInletand the llp.

The engine-inletair temperaturewas matntalnedat 710°A 5° Rby a oomhusticmheaterin the air supp4 Mne. ~ fuel-alrratiofor the combustionheaterwas about0.002. Ths effeotof theslightresultIng cmrbsdmtlcinof the ohargeair a the enginecombustionIs not lmounbut Is believedto be small.

NAOAIM E50H21 “

Runs Wsre IlpdeWith Unifomufuel ln$mkbl

7

for all flame holdersand several flameholdere were also run with annularIn#eotim. R&flameholder2, a few runswere made In whioh unequalfuel pressureswere imposedon the fuelmqnl.foldsIn an effortto blend ~uallyfrmuannularto uniforminJeotlmo Elow-outwas deteotedby observa-tion of the flazusthrougha perlsoope,by the suddenohangeYn soundlevel,- by = automaticflmue-deteotiondevioe..Ths smols usedand methodof oaloulatlcmof oombusti- effioienoyare outllnedinthe appendix.

RESULU!SAND DISOUSSIQll

The radialdistrlbutiausof fuel-airratioand totaland staticpressuresat the ocmbustlon-ohemberInletwere measuredIn ordertooheokthe possibilityof regions of separatedflow m lrre@drvelooitycm fuel d2strlbution.The typesof fuel distributionobtainedwith unlfozmand annularInJeotionare Illustratedinfigurs5(a). As previouslymentimed, the results=e mnslderedto be qualitativeand indloattveof onlyths trends. The fuel-airratiofor mifom inJeotiondid not vary greatlyoverthe outer10 inohesof radtusbut deoreas~ slightlytowardthe oenterofthe mibustion ohambed. Annularh jeoticmproduoeda rioh regionoenteredmound the 5-inohradiuswith rapidlydeoreasimgfuel-alrrattostowardthe oenterand outerwall of the oanbustlonolianiber.The distributimsof fuel-airratio observedfor otheroperatingOarlditialsindioatedthat annularinJeotlonprovideda looallzedregionof nearly“stoiohianetriufuel-airratio,em for very le=over-allfuel-airrattos;whereas-m ~eot~~ distrlbut~ fuelmore evenlyfor all fuql-airratios.

Typioalradialdistrihutimsof totalto statiopressureratioaheadof ths flameholderare shuwnin figure5(b). The radialpressureratiogradientwas very largenear the Innerand outervans of the diffuseroutlet,but tt Is evidentthatno extendveregionsof separatedflow existedne= the walls. The ml?ibustlmlresultsgivenhereinapplyonlyto the p-iouhm mudltlons ofpressure,velooity,and fuel distrlbutiauat the ocaibustton-dmiberinletprodumd by the test engineand theirdegreeof applicabilityto otherOonditlonsof fluw is unknown.

Plots of the bastodata for eaohflame-holderoonftguratiaare shownin figures6 to 15. For eaohflameholderthe simul-taneousvariationsof e-ut-no=le vess~e =tlo p4/P5}ocmibustlau-chamberpressureratio P4@2j oawtia-omer-~etl&mh number M2’, oaibustion=ohamber-outletpressure P4, @s-flow

f=tm P$5b5$tlonsof fuel-air

~“ ‘““ “kM.Am E50E21

and ccmibusticmefflolencyq are givenas funo-r&tlo. Inasmuchas ctibuE&ion=ohamber-inlet”

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velocity,pre6mre, d fuel-alrrat.lovary eimultaneotif31y,theindividualeffeotsof thesevariablescm performumeaxe not separatedIn figures.6to 15. The trendsshownthereforeapplyonlyto thespeoiflocombustioncmnditlonsindioated.Superimposedon the mrvesof milxzstlon-ohamber-outl.etpressureare ltiesdenotingthe bluw-outlimitsfor both uniformand smnulsrI@eotlon. Data m?e shownforuniforminJectlonfar dl flameholdersand for.annularin~eotianfor severalflameholders. The dataare codedfor oonstantaltitude,whiohas previouslydknzssed tipliesa constantenginebellmouth-Inletpressure.

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Engineoperatlnl?Oonditians.- JhasmucK-asall runsweremadewith a ohokedexitnozzle,the ratioof nozzle-inletor mmbustlon-ohamber-outletPregsureto throatstatiopressure 24/P5 shouldinthe lde&Lane-dimensionaleasebe a funotiononlyof gas temperature “and the thermcd~ynamiopropertiesof the gas,andthereforeindepend-ent of configurationor fuel-air-ratiodIstrlbution. Departurefrcan -the Idealon6-dlmenshuilmnoepts will producediscrepanciesIn theocmbustiontemperaturesend effioienoiesoomputedby the methcdout-llnedIn the appendix. The e~erlmentalexhaust-nozzlepressure-ratiodata (part(a)of fIgs.6 to 15) showthatthe pressureratiois independentd altitudebut dependenton oonfi~atia as wellas t~e of fuel injeotion.

The cambustian-ohambertotal-pressureratio P4/P2 for eaohflsmeholderis ne=ly independentof fuel-airratioand altitude.The pressurerirbioIs mmstent beoausethe’inareasein momentumpressuredropwith increaseinfuel-airratioIS oounterbalanoedby a deoreasein fric%lon+ressuredrop. The differencesIn pres-sureratiobetweauflameholdersis a resultof differmoes infrlothn pressuredropand can..ustioneffioienoycharaoteristios.The pressureratiovariedfbcmapproximately0.90for flameholderswith high blookedarea to about0.94far low-blooked-areaflameholders.

-.

The mmhustl’on-chamber-inletMaoh number=S ocamputedfrcunthemeasuredtotaland statiopressurbsat instrumentstathn 2 upstreamof the flaw holderand adJustedto the oomhustlon-damberareabythe isentiropio-flowrelations. For thisreasonthe Maoh nuribers=e designatedM2t. ThisMaoh numberdoesnot actuallyexistatthe flame-holderInletbut is oonventkmallydefinedon thisbasisfor cmmenienoe of referenoe. The trendof Maohriuberwith fuel-air ratiowas similarfor eachflameholder.” TheMabh numberdeoreasedwith increasing$7x&air ratio,remhing a m?.nimumvalue between

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2 Itfwfl EME50H21 ~’ -- 9.

0.135and 0.150at the highestfuel-airrattosand a maxlmumovalue* with annularInjeotionof slightlygreaterthan 0.220at fuel-air

ratiosaround0.03. A separationin the data for ~form anda annularInjeotlonoccurredas a resultof the changein mnbustlon2 efficiencysubsequentlydlsoussed. For a few of the flameholders,

alightseparationalso ocourredwith altitudebut was so smallhmost casesthat It was obsmred by e~erimentalscatter.

Stableccunbustlonllmits.- The reductionin ccmbustim-chmtber-outletpressure PA with increasedaltitudeis shownin part (d)off@ures-6 to 15. h mmbusttan-chaniber-outletpressurefor a givenaltitudeticreasedwith fuel-ah ratio in orderto satisfyocntinui~y.For uniformlnJeotlon,burrdngwas accomplishedfrcunslightlyoverone atmosphereto approximately2/3 of sea-levelatmosphereoutlet

The burning-~essureremgewas extendedwith annular,“

pressure.injectionfor acmeflameholdersto lessthan 1/2 atmosphere.

d The burnl& blow-outlimitssu?etndlcatedon the plots afcauibustion-chsaiber-outletpressureby the dashedllnes. Althoughonlya singlellne is shownfar each limlt,the blow-outregionIs.in realltya band of fuel-airratioslocated=ound the dashedllnes. The band probablyextendsover a regtrmof about 0.005infuel-ah ratio. Thisfact e@.sins the appearaaoeof omaeionalstibleuperatingpointsoutsidethe blow-outlimttsfor sczueflameholders(forexample,flg. 9). b general,the fuel-airratioforleanblow-outInxeased as the simulatedal.tttudeincreasedforboth uniformand annularinJeotlon)whereasthe rioh lhlt fuel-airratiode6reacedwith Increasingaltitude. The operating range offuel-alr ratiosthus deoreasedwith increasingaltitudefor allflaneholders. The altitudeabovewhiohburningwas not possiblewas reachedonlyfor flameholder1. Annularinjectt~ extendedthe leanblow-outfuel-alr~tto llmltfor all flameholderstives-tlgated. The richerzoneof fuel-airratio provided by annularinjectdonapparentlyprduoed a more favcmablemixturefor ocabus-tion in the regionof the flame-holderguttersat low over-allfuel-air ra%los. The maximumoperatingrangeof fuel-alrratiosvariedfl’a a lean llmltbetween0.04and 0.05to a rtch llmltbetween0.07to 0.08for unlfonnin$eotia at the altltudesinvestigated.The leanllmltwas extendedto approximately0.03fuel-atrratiowith smnulerinJeotion.

Gas-flowparameter ● - As shownin the appemdix, the gas-flow~ameter p5A5/W5 is a functionof the ocuubusttonefficiienoyandthe ccmbuetion-chamber-outlettemperature.The &as-f’lowdata are

. presentedin this famto use as a measure of

.

becausethe gas-flowPam&ster Is ccmvenhnt

mubustion perfozmuume,for estimationof

a

10 .. N4CAk IZ50E?1 “ :

enginethust, end to detezzuinethe air-fla rate throughtheengine. The gas-flowparameterincreasedwith ticreasbg fuel-airratiosup to approximatelystoiohiometricand thendecreasedslightly. Differencesbetweenflameholderswere small;far -exemple,at a fuel-airratioof 0.05 the valueof ga8-flowparemeterwas frcau61 to 64 for all flameholders. Becausecombustioneffi-cienciesfor annularinJectionare lowerthanfor unlfozminjection,the gas-flow+xmuneterourvesfor the two typesof inJection sepa-rate considerably.The gas-flow~ameter for most of the flameholderswas independentof altitude;for a few flameholders,however,a slightdecreasein the gas-flowparameteroccurredatlow fuel-airratiosas the altitudewas increased.

Combustlcmeffioienoy.- The curvesof combustionefficiencyqfollowthe sametrendsas the gas-flow-psmmetercurves. As pre-viouslymentioned,oonihstiranefficlenoyis influencedby ccunbusthn-chamber-inletpressureand velocityas wellas fuel-airratio. tigeneral,the co,nibustlonefficiencyIncreasedas the fuel-alrratioincreasedup to approximatelystoichlometrioand thendecreasedslightly.The combustionefficiencyfor a few of the flameholdersdecreasedas the altitudeincreasedbut was independentof altitudefar most configurations● The mmbustion effloiencyfor aanulerInjectionwas generallylowerthanfor uniforminJectionatcoqperablefuel-atiratios. The measuredvaluesof uniform-lnJectlanccmibustlonefffcisncdesvariedI%om 0.7 to 1.0;whereasfor annularl@ection the rangewas fha 0.4 to 0.9. Visualobservationduringannul.ar-inJectlcnoperaticmshowedthatflamewas presentonly Inthe centerof the combustionchsaiber.

Data obtainedduringrunswith blendlngof the two fuelmeni-foldsare shownIn figure7. A smoothtransttia from annularinJecthn at the lowestfuel-alrratiosto uniforminJeotionathighfuel-alrratioswas acocmplishedwithoutoperatiaualdifYhulty.The ocunbustion-effioienoycurvefollowsa ~adually Increasingtrendwith increasingfuel-airratto.

●

Compartsonof over-allperfcmmmlce● - The factorsto be con- ..slderedin an over-allperformancecomparisonare pressurelosses~combuetim efficlancy,and operatingfuel-alr-ratiorange. usually,the cmlyrequirementIs to obtainthe highestpossiblecombustionefficiencyaccompaniedby thewidestattainableoperatingfuel-air- - -ratiorangeand the luuestpressureloss. For someapplications,however,an evaluationof the effectsof altitudeand fuel-al??ratioon &ese performanceparameterswith referenceto the fllghtplanand diffuseroperatingcondltiansis necesssrybeforethe mostdesirableconfiguration= be selected. Overthe range of altitUd06

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mCA m E50H21 -.*.-

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investigated,the tidestoperatingrangeand lowestleanblow-out* limitsfor both uniformand annularinjectionwere obtainedwith

flameholders3 and 10. An approximateortsm of efficiencies

kand pressurelossesoverthe rangeof steadyoperatingconditionsmay be made by ocxugm?ingmaximumcombustionefflolenoyand oombusticm-ohamber-pressweratios:

holder

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12345678910

ccmbustionBfficlelmy

0.92.88.96.90

1.00.98●95.99..91.94

ccmibusthl-ohamber -

pressurerat10p4fi2

0.93.92.94.92.91.93.90.92.92●92

The data showthat oombuettoneffloiemoywas nearlyindependentofthe mubustion-chambsr-pressureratio. An efficiencyvariatianof12 peroentooourredwith a pressure-ratiovariationof only4 per-cent● l!henwu3mnuefficienciesof flameholders3, 5, 6> 7} 8~and 10 were between0.94and 1.00and may thereforebO consideredof comparableperformance;flameholder5 had the highest~efficienoy. The mibustion effioiemiesof-theotherflameholderswas from 0.88to 0.92. On the basisof the highestoonibustioneffioienoy(O.7 to 0.95) with reasonablylow pressuredrop andwidestoperatingrange obtained,flameholders3 and 10 are mn-sideredto be the best of the 10 flameholdersinvestigated.Flamehold= 3 had a slightlylowerpressureloss;whereasflameholder10 had a slightlywideroperatingrange.

Effeotsof gutterwidthand blooked=ea on ccmibustionefficiency.- The ocmbueticmeffiobnoy Is plottedas a functionofgutterwidthfor two nearlyconstantblookedareas,fuel-airratios,ad ccmibustton-ohamber-outletpv?essuresin figure16. These ourves

. are WOSS plots Of f i-es 6 tO ~ ● For thesefuel-airrattosnearstoiohlometrioand fcm thesepressuresof approximatelyone atmosphere,

.~“ - “.-’”

XL

12 ~“ NAOAM E50H21

.“

gutterwidthhad littleeffeoton the ocdbustloneffioienoyfor agivenblookedarea. Data for a fuel-airratioof 0.045 (notshown)had a similartrendat aboutthe samepressureleveh. Insuffloient

R

datawere obtained,however,to determinethe gutter-widtheffeots3

at lowerpressures.

The effeotsof blookedarea on oombustloneffibienoyare shownh figure17 for similar oonditims of pressureand fuel-airratio.A generaltrendof increasingeffioienoywith inoreasedblookedarearesultedfor gutters1.50and 2.00lnoheswide. An inoreaseof 5 to 8 perpentin ocmtmsticmeffioienoyooourredfor an inoreasein blookedarea&om about40.0to 62.0peroent. The effioienoyofflameholderswith 1.00-inohgutters,however,reaoheda maximumatan intezmwdiatevalueof blookedareaand dimreasedas the blooked -area inoreased.The ourvesfor 1.00-inohguttqm are more subJeotto errorthanthosefor widerguttersbeoausetheyare basedondata for onlythreeflameholders. A ocmsistenterrorin the datafor any cm flameholderoouldtherefareshif%the entiretrend, “Partioukmlyin view of the relativelysmallohangesin effio~enoyinvolved. “The ourvesfor the widergutters,however,are the resultof orossplotsfiotudatafor five flameholdersand are ooneidered .

more aoourate. The inoreasedeffiolenoywith izmreasedblookedm?eawas attributedto the involvementof a largerpercentageof theinocdng fuel in regionsfavorablefor ocmibustion.

Correlation of operatingr~ data.-metheol?y or buz’d.ngin the wake of bluffbodiesdevelopedin references2 and 3 andindependentlyin referenoe 4 postulatesthat ocmtinuousignithnoooursas a resultof transferof hot gasesfiaureoiroulatingeddiesor vorticesimmediatelydownstreamof the bluffbody intothebound-y regionof relativelyooldfuel-air?n.ixtures.The tempera-ture of the boundarymirhre oonseguentlyinoreasesas the flowprooeedsdownstreamuntilthe appropriate@ition temperatureis

——

reaohed. lhmm a heatbalanoebetweenthe heat-supplyrate ~uiredfor ignitionin the boundaryzoneand the rate of heatflow ficmnthe eddyregion(Seereference2 for a detailedderivation.),It canbe shownthatfor a givenfuel-air-ratiodistributicmand for aocmstantinlet-airpressureand temperature,the followlngrelationspplies:

M@= @(f)

where f is the fuel-airratio, n is the width of the bluffbodr(gutter) , euldindependentof

@ is a funotion&l notatkm. The relationis -blookedarea. The value of 0.45for the emonent a,

.

NACAm E50H21 ~ ‘“’”””9”- 13

.

detemlned emplrioallyIn referenoe2 for guttersof lomg spau,1ss used for the plotsWesentsd herein= similaroo?%elattm was

obtained,however,when an expment of 1.00was used.

Crossplotsof the faired blow-outfuel-air+rattodata of this

reportas a funoticmof the ocarelaticapemmeter ~ t/n””45 arepresentedIn figure18. Curvesam shownf= ocmstantpressuresof1400and 2000poundsper squarefoot absolute. The de@ee of cor-relationis goodfor all ourvss. The data spread1s less than halfof the gen&al trendin all oasesand iswithin the limitso% repro-ducibility.The soatterx be ~1.y causedby slightdifferencesinfuel-airdistributionfa the dmerent gutteramaqments. Althoughit is possiblethat this oorrelatlaumay be enttrelyfcmtuttous,thesimilarresultsof the referenoereportsadd considerableoredenoetothe fundsnmntalnatureof the mmzelaticm. -

-~s~ of flms 18(a)* le(b)M that deo=+s= ..pressureleveldeoreasedthe operatingfuel-a~ratlo raagebyInoreaslngthe fuel-airratiofcm leaublow-outand decreasingthe

. fuel-airratiofor rioh blow-out. As the inletMaoh nuniberwasInoreasedcm the gutterwidthwas deoreasedfor a givenpressure,a stiilarreduotionin operatingrmge ooourred. The operatingrangefor a pressureof 1400pourdsper squarefoot Is extremelysensitiveto inletMoh number. Referenoeto figure18(a)shuwsthatan inoreaseIn Maoh nuniberof 36 peroent,resultlngin aninoreasein the correlatlaparameterfk-am0.11to 0.15,produoeda demease In operatingrangeof nearly75 peroent. Compen-sationfor the fnorsasedMaoh numberby increasingthe gutterwidthto maintainocmatantoperatingraugewouldrequtreapproxi-matelydoublingthe gutterwidth. The slopeof the lean operatinglimltourveIs very largefor the lowervaluesof the oorrelathnparameter;Ocmsequemtly,furtherInoreasesIn gutterwtdth ordecaeasesin Mlet Maoh nuuiberwouldyieldvery smalldeoreasesinlesnblow-outfuel-airratio. The rloh llmttsfor the lowervaluesof the ocmrelationparameterare at fuel-airrattosgreaterthanthosefor maximumoombustion-ohauber-outlettemperatureand arethereforeconsideredsatiefaotwy. E’uturedevelopmentof ram-~etocmbustorsfor wider operatingrangewill thereforeprobablyrequirecontrolledfuel-air-ratiodistributlm ti ocmiblnatlawtth flame-holdingdevloesdesiguedto producemm?e favorabletypes of reotr-mlathg vortexflow in the flaw-holderwake or the use of speoialpllotlngdevioes.

.

,:-

—

suhMARYol’IqsuIm

An altitude-test-ohamberinvesttgatlonof the ocmbustionperfcmmanoeof 10 flameholdersin a 28-inohrsm-~etengineovera rangeof simulatedaltitudesfrcun40,000to 55,000feet and ata simulatedflightMaoh numberof 2.0 @ve the followingresults:

1. A 2-inohwide 60° gutterflame”holderwith 45-permntblockedareaand a 2.50-inohtide 60° gutterflamieholderwith60-peroentblookedarea had the most favorablemubinatlon of wideoperattngran@, high csombustIon effIolenoy,and low pressurelosses.

2. Far theseflameholders,stableopeZ%tlonat a simulatedaltitudeof 50,000feetwas obtained~with inJeotlonfimu two fuelmanifolds(uniformInjeotion)fran fuel-airrattosof approximately0.040to over0.065. bJeotion ficma singlefuelmanifold(annularInJeoticm)etiemdedthe leanblow-outfuel-airratioto approxi-mately0.030. Combustioneffioienoieswere from 0.7 to 1.0 overthe operablerangbfar uniformtiJectionand fi?om0.4 to 0.9 forannularI@eotion. Combustion-ohambempressurelosseswere 6 to8 percentof the mxubustton~ohamber-inlett~talpressure.

.

3. ~ general,annularinjeotionprovided100allyrioherandthereforemore favorablezcaesfor ocmibustlonfar the lean over-allfuel-alrratiosthanunlfcumti~eoticmand resultedIn a reduotimin leanblow-outfuel-alrratio. Cwibustioneffiolenoieswerelowerwith aanularlnJeotionthanfor unifom inJectlonat comparableover-allfuel-alrratios.

4. Ohangesin gutterwidthfhxm 1.00to 2.50 inohestitho~tant blookedarea had no appreolableeffectun mubustlomefflolenoyovera mnge of fuel-alrratiosfrom (?.045 to Q.065and for pressuresof approximately1 atimoephere.Increasingthe - -

—.—

blookedarea frcxn40.0to 62.0percentwith gutters1.50and2.00tioheswide resultedin an inoreasein mxubustlmneffIoienoyof 5 to 10 peroent. For 1.00-lnoh“widegutters,increasesinblookedareafiau 42.0to 48.0percentresultedin an Inoreasein effloienoy;furtherInoreaseto a blookedarea of 55.0percent,however,resultedin a deoreasein oombustlonefficiency.

.

NAOAW E50H21 ~-”-”””.

5. The lean and rich IMw-out fuel-air~atlodatawere o~e-+ latedby use of the rattoof mabustion-chamber-inletMach nuuiber

to the guttertidthraisedto the 0.45puwer. The degreeof ocu?-relatlonobtainedservedta verifythe work of previousinvesti-gatorsand to -nd theirwork to largersoaleoombustors.Theshapeof the ourvesobtainedindioatedthat furthergainsby

g Imreaslng gutterwidthbeycmd2.50 Inoheswouldbe very small.

m’

Lewisnight PropulsicmLaboratory,Hatimal AdtisoryCmmittee for Aeronauttos,

Clevelsnd,Ohio.

l-s

.

“

.?

16

A

a

f

6

M

n

P

P

R

T

t

w

2’

v

The following

area, sq ft

~ -

APm.mx5 - CALCWATIONS

symbols -

symbols are US9d. throu@out

empirtoal ccmstant

fuel-air ratio

aooeleratlondue to

Maohnumber

@ter width,in.

gravity,ft/0ec2

total preseure,lb/sq“ftabsolute

statlo pressure,lb/sqft absolute

@S ‘oonstant,ft-lb/(lb)(%)

totaltemperature, ‘R

statIc temperature, OR

WOlght flOW, lb/890

ratio of speoifio heats ..

combustion effiolenoy

~’ funatlonaln@atLon

Subscripts:

2 Cxxldi.tions at

2’ conditionsat

4 conditions at

5 ccmditdons at

NAM mE501121.

.

the report:

ccmbustim-ohamber inlet .(station 22P)

station2 adJuetedto combustion-chamber

combustion-chamberoutlet(station280)

exhaust-nozzle throat (station297)

—=-mm=-*

.—. .

—

---

..

-.:.?

I ... .,... . .

*

area

.

1

3 I’w2ARM E50H21

.

Oalmlatim

-

Win==—= ‘“= 17

Of Combustion~iCt9nO;

The flow at the erudneexit is assumedto be idealone-dimensional% uniform flow and the as&mption Is tie that the Maoh number at the

2 exit-nozzlethroatis 1.0 with a flow area equalto A5. Under theseconditlaasthe followingrelationmay be derived:

()’452M (y+l)T5=—w~ ZR

(1)

where y is the valuefor averagebetweentotaland statto tempera-ture at the throatend for the prevailingfuel-airrattoand R is53.5foot-poundsper poundper OR. TIM _uted temperatureT5 isthen oorreotedfor the heat reJectiaato the ombuaticm-chamberOoolingwat@ ●

dThe oaubusti~ effiolenoy Is defined as

‘T5-T2)a~ual

~ = (T5-lC2)idml(2)

ts obtainedfz@ reference5.

of p~ usedwas the numerbaltubesand fourwall statioorifices.the cxmmutedvaluesof T. end n

where the ideal temperature rise

~ oomputing T5 the valueaverageof eight~il.ing statloThe possibllttyof inaaouraoyindue to the many assuu@icms involvedis ~bvious. The magn?tudeof-the errar,however,wouldprobablynot be greatlyaffectedby oon-figuraticm,and valuesprobablysatisfactoryfor relativecowarisonwere obtained. A plot of the relations between eqyations (1)and (2)Is shownin figure19. The gas-flowparameter p5A5/W5 tsplottedas a funottonof fuel-airratiofor variousoonstantcoxtibus-ticm effiol=oiesand ocmbustion-ohaniber-outlettotaltemperaturesfor an inlettemperatureof 710°R. The plotmay be usefulforevaluatia of ccxnbustiontemperaturefrom the data presentedinthe reportor to establishthe relatlms betweenthe other ocaibus-tion -iables .

.

.

18 NACA RM E50H21

●

~.

. Rm’ERmcB

1. Jones,W. L., Shillito,T. B., and Heu–el,J. G., Jr.: Altittie-Test-ChamberInvestigationof Performanceof a 28-InohRam-Jetlhgine. I - Co.uibustionand OperationalPerformanceof RburCcmbustlon-cheuuberConflguratione.MCA RM E50~16,1950.

2. Wlllhus. GlennC.: BasloStudieson FlameStabilization. Jour.#Aero. Sci., vol. 16, no. 12, Dec. 1949, pp. 714-722.

3. Goss, W. H., and Cook, mory: The Ram Jet as a SupersonicpropulsionPlant. SAE Trans.,vol. 2, no. 4, out. 1948,PP. 642-657.

4. Reiter, Sidney, ad DeVault, R. T.: Experimental Studies ofSupersonic Raqlet Cgmbustlon. USCAL Rep. 4=9, Aero. Lab.,USCLA, June 1848. (Navy Contract NOa(s) 8257, Items 2 and

5. Mulready, Riohard C.: The Ideal Temperature Rise Due to theConstant Rmssure Cdmstlon of Hydrocarbon Fuels. Meteor

3.)

Rep. UAC-9, United Alroreft Corp.; July 1947. (Proj. Meteor,Bur. Ord. Contraot NOzxl9845 In moderation with M.I.T.)

,

.

..:.

8 .

-...

I k

.

.

E!

, ,

1

!:”..-- . ...! ,,, 1,

, s

S6srt

I combus$on ~ ‘1,

l.\timber :.,.,

.-!.. \ ,,

Longerons~ -

1!E!

1!P

.

g

. . .

. . . ..-.

.

.

I # L .

86!n.

Ii’!4

i!r

,*“”

r ,

n

u

titter

.

?lam Q3ea.

I

.

.

.

-lr

(a) A holller 4; blcdsa -, 40.5 -; m Wiw, l,SJ ~.

..,..,

1 , 86ST .,

, .,

lom

8 B481-2128

I ,1.388

t *

(e)m ho-ldm 6; monkd Llron, 60 pemunt;- Wi&hIl, i?.ooilldw.

m4m=4. -o=M.m=L ~tio alagam (ICfume ~.

.

.

mltk?r

#

..1

(f)= -e; b~ -, 58 wrmnt; gnttorwidth, 1.20 imhea.

-4. - CaItimma. achamtia d.. d fk holdmn.

,,, -

, ●

E!

,,,.

1 i.,I . em: .’.,..

,....11,,,,,,f:

, *4S1-2129

I ,

.

lxm, .

.

—

1“P

.

.

1.

,, .

. t-wvr. ‘r.?i-.

, ,.cM.la

1 ,

B!

I(1) - holds 9; b~ -, 56 -; - Viwl) 1.40-.

mm=4.-~. ~tia luagmm d f- Iddnm.

i!r

I

.

‘ Lzli?-m, . l“, 86!n

f

.’.

1“

ii

1!r

I

WA W E5CE21 33

.

.

.

.

●

9

●

●

Inner~ body ~jeothn “’

08‘ o Utiorm❑ Annular

06 u

/ Y

\

\ n

04

02

(a)Ty@oal f!uel+lr ratio distribution.1.07

1.06 ‘Inner

~ body1.06’

1.04

1.0s ‘

l.oa A

1.01

1.00.2 4 6 8 10 1S2 14

Radial dtstanoe from oenter line, in.

(b] Typical pressurematio distribution.

F18ure6. -Radial diotributlon of fuel-alr ratio and pressureratio

●

at mnlnmtion-ohamber inlet.

“~-”

IMCA RM E50H21

.’

I

Altltude(rt)

0 40,000❑ 48,000

S!*o

1.9

+ q -

1s8

1.7.(a) IMmtet-uomle pawssure ratio.

,.

●eo

-a ~ “2

.. 0- - 47 * L—

● 10●W .03 .04 ●06 .06 .W7 .08

Fue141r ratio(o) Combuethn-ohamber-inletMaohmmber.

Figure 6. - Perfomame ourves for flame holderL Gutterwidth,LOO fnoh;blooked area, 42.0 peroent;uniform lnjeothn only.

.

.

.

.

.

.

I?ACARME50H21

.

.

.

.

. rlah

Q600“

9400

2200

moo L

1800 d ——.—1600 L bl~-out

1400LAltitude

moo ‘(ft)

~ 40,000❑ 46,000

1000

600(d) Oombustlm—ohamber—ou tlet~ssure endblow-out ltits.

(e) Gas&low faotor.

“1.00” uo

+ - ~o

~. -

.60“

.60

●40.● 08 805 .04 .06 .07

Fuel-aL?rat%0●O6

(f)Ocahstiuneffislenoy.

=-e & . a~~ludedo.

Performame ourves for flame holder 1. Gutterwidth,1.00lneh~blookedarea,42.0pereent;unifomuin~ecthn only.

36 NACA RM E30H21*.....d*..,.

.

.

G“i!?

(a)mwmst-nozzle pressureratio.

.,

.30

#

.20 %

11

● 10 - - *●02 ●O5 .04 .06 ●06 .07 ,08

Fuel+lr ratio

(o)Ccmbuettoa-ohamber=-inletMaohnumber.

Fimre 7. - Performsme ourves f’orflame holder i?. Gutter width,1.00 inoh; blooked area,

—

.— ---

,..-.

.

.

55.0 peroent. .- .

.

.

.

.

m ES(H21 37

moo

2400

u:&rm 0“

Sooo— — ~blow-ou. A\

5 9 * &’

u

“

~~ ‘

\Moo

i%Iform rtohblow-out

lm d

$P o

1400 AAnuularl

/P’

blow-out~ >1200 ,L

r* ~eetion Altttude

UniformBlend5ng(ft)

1000 0 40,000> 46,000

: 50,000

600

(d) OombuetLm+ha@m=utlet messure and blcm’+utlimlts.70

a

60— — — — —

60 D>

40 D(e).Gaa-tlowfaotor.

An I I kFtel-alr ratio

(f) Ccmbuetloneffleienoy.

Ftgure 7. -Comluded. Perfomame curves for KLame holder 2. Gutterwidth, 1.00 inoh~ blookedarea, 55.0 permnt.

38 IMCA W ESlE21

,-

1

InJeotlcm AltitudeUnlfom Annular (ft)

“ot

40,0004J3,000

: w 60*000

1.9 + ~ ~b ~ ~

~ o1.8 .

1.7(a) Ea$laustmsme msmre ratio.

,.30

-1\● go

o

● 10 .● 02 .03 ●04 ●O5 .06 ●U7 ●09

Fuel+ir rat10

(o) Cmubuatton-ohamber-inlet Maoh number.. . .

.

.

.— .

●

Figure 8. - Performanceourves forflameholder3. Gutter width,%00 lnohes~blookedarea, 45.0 peroent.

.

●

✎

r

EM E5W21 39

8600“

2400

2200

2000

1600

1600~ {

1400rleh

lEOOLblow-out

+Unlfo& lean

1000 “blow-out

#kinlnllarlean h$ ediion Altltude

blow=out U!lifomllAnnuw (rt)800 0

~ Z:E: * 60,000

(d) Caibustlon-ohamber-outlet preemu?eand bl~ t I..lalltso

g 70 .

jlg60— — — — -

%$“$a ’60u

c? 40(e) Gas&low faotor.

L 00

~: .=*

d

!

i!d 7●60‘

.ij*

/ -.

h

,4C. I● 02

Figure 8. -

●03 .04 .06 .0? .08Fue14Nratlo

(f) Combustioneffloienq.

Conoluded.width, 8.00

p~rO=Oe curves rOrflameholder 30 Gutterimheo; blookedarea, 45.0 peroent.

Altltude(ft)

o 40,000❑ 48,0000 50,000

990

1.9, m ❑ &.n > ‘ .“u

. -

10e 61

107 .

.—

*

.(a)Exhaustmossle preseure ratio.

(b) Ccmbuetion+hambertotal=presmreratio.v

.02 .03 .04 ●05 .06 ●07 .OaF%el-alrratio

(o)cambuetion-hamber-inletMaohnumber.

Figure 9. - Performancemrves for flame holder 4. Gutterwidth,1.50 imhes: blooked area, 40.5 peroent~ uniform injeotion0?14.

NACA RM E5QHZ1

b

*

F

f?600L

mm

1600

1400

1000.

600.

600

(d) Combnetlon+haniber-outletpessure and blow-outlimits,

(e) Gcukflow facstor.

1.00

●8O

●60

●40.09 SOS ●04 ●O6 .06 ●07 ●08

Fue141r ratio(f) Ccunbuetimeffioienoy.

Figure 9. - Conoluded. Performanceourves~orflameholder4. Gutterwidth, 1.50 lnohes; blooked aren, 40.ESperoent; uniform lnjeotlononly.

41

42 N&2ARME50H21

.

(a) Exhauet+omle pressureratio.

(b) (haabustlon=diambertotal-pressureratio.

I I I I I I I I I I I I I

●30

1 I I 1 I I I I I

● ~vl I 1 1 1 I I I I I .,.

.02 ●O3 ●04 .03 ● 06 ●07 ● 08Fuel+ir ratio

(0) Cdilet ion+$hamber-inletMaoh manber.

Ftgure 10. - Performame cnu?veefor flame holder 6. Gutter width,2.00 inohes; blooked area, 60.0 peroent.

1

*.*.-’ --- .

.

.

.

WA RM E50H21

Ill

(d) Cambustlon-ohamberatlet pressure and blow-out limlts.

70 .

60‘ w - A

60

40—(e) Gas-iClowfaotor.

1.00

●8O .b

● 60

,40● 02 .05 ● 04 .05 ●06 .07 .08

Fuel-alr ratio(f) Ccmibustion effleienoy.

Figure 10. - Conoluded.width, $?.00

Performenoeourvesfor flame holder 5. Gutterinches; blooked area, 60.0 peroent.

44 NACA RM X50H21

o 40,0i30

1*9’

1.0

1.7(a)&haustAossle~essureratio.

(O) 0aubue610n-ohamber-inletiMaoh rnnnber.

B’lgure 11. - Performanceourveeforflameholder6. Gutterwidth,1.80 lnohee~ blooked area, 58.0 FOroent; uniform lnjeotlcm 0n4.

.

.

.

I?MA RM E501121

.

.

r

*

8600-o

. \

/ y

\ &\ ~OllU rloh\blow-out

vIMrorm leanblow-out- .

1600

1400

Altitude

o 40,000

600

600

1.00s

J“.60*

II

i . .

: .60

“% T .●40,02 ●03 ●04

Fu&z ratio●06 .07 ●O6

(r) o~tta drIOkQY.

Figure I.I..- Oonoluded. Per~omenoe ourveafor flameholder 6. titter width,1.90 lnohee; blookedarea, 66.0 QePoentj uniforminjeotion only.

46 NACARME50H21 ““

.

Uhirol.ml,@llmlaro

1.9 ‘

1.s

107(a) &@mzat+ozSle pressure ratio.

.,., ..,, ..=.=_.

:..

*—

.. s-

.-. .

8 #

IIbm1.0% -..

j~. .9 “’““,. .,

— — — — .... F + ❑

;

g~ ●8 “+ (b) (kmbtmtiau+hamber total-pressureratio.

.30

.20

●10.09 .03 .04 ●06 .06 ●07 ●08 ●09

Wel-air ratio

(e) Combuetlon-chamber-inletMaoh number. ,

..—-.

. .

-._:

. . ..

n

Figure12. - Perrozmamec)urvesforflame hol&er“7. Qutter vi~th, 1.38 “’” ““imhea; blooked area, 6$?.0pement. .

NACA RME50H21 47

(d) Ccmbustloa=ohadmr-outletpaessureand blow-out Madts.

1F

.02- 903 ●04 .08 ●O6 .07 ●0s ●O9Fuel-air ratio

(f)CcmbuetlonO.fflotenoy.

Figure 19. - conoluded. Performmoe ourvesfor flameholder‘7. Gutiterwidth,1.38 inohea;blookedarea, 6$3.0peroent.

.

NAM RM E50H21

(ft)

(a) EMmwt~zsle pressureratio.

(b) Ombustlom-ohamber totalqmessure ratio.

20.

a- ~ = a’#1 ❑ 8

G w Ou

10●05? ●03 .04 ●06

FuelGZ ratio●0? 908

(o) Cmubustlon-ohamber-inletMaoh number.

Figure 13. - Performame ourvea for flameL 00 tich; blooked area, 48.7 peroent;

holder & Gutter width,uniform injeotion only.

.

.

iG-8

--

7

.

.

.

NACA RK E50H21 49

8600

Moo

2200

blow

1600 -

.1400

lmo Altltude

1000Q 150,000

(d) Ccudmstion+hamher-tlet prensure and blow—mt limlts. .

70

.-~ 40

(e) Qas-flow f!aotor.

1.00

g; .80$a

I3~ ,60

U:● 40

.02 ●03 ●04 ●O6 ● 06 .U7 ●O6Fuel-dr ratio

(f) Combustioneffieienoy.

Figure 13. - Concluded. Performame ourvea for rlame holder 8. Gutterwidth, 1.00 inch; blooked area, 48.7 pement; uniform Injeotiononly.

.

.

MA(2ARMS$50H21

*

I

._Altitudem)

0 40,000

: ?O:Os..

.. .

n—o

❑❑

(a) Exhaust+ossle pressureratto.

..“b

—

8,. ,

.●

(b) Mabustlon-ohember total-pressureratio~

.02 .03 ●O4 .06Fuel-% ratio

●O7 .0s.

*.

(o) Canbuemxwmamber+let Mach number.

Figure 14. - Performance ourves for flame holder 9. Gutter width, ‘“ “1.40 inohesjblooked area, 55.0 peroent;uniform injeotiononly.

NACA RM E50H21 51

.WOO ~

moo ~ /

moo — — —unifc&rm 3

blow-outi+ MIIMhml\

1600‘blow-out

/

~ z’1400‘ /

1900 Altltude(ft)

o 40,0001000 ❑ 4s,000

o f50,000

(d) Combustion-ohaniber-outletpressure and blow-out 15mlts.

—(e) Gas-flow factor.

1000❑ b n %

●80 o

●60

●40.02 ●03 .04 .05 ● 06 .07 .08

Fuel-air ratio

(f) Co3nbustiaueffioienoyo

Figure 14. - Comluded. Performame Ourvea for flame holder 9. Gutterwidth, 1.40 lnohea; blocked area, 5#.O peroent; uniform ln$eotion only.

NACA RME5~1

tijeotion Altitude‘mllformAnnular (St)

o 40,000t. 46#ooo

: * 50,000u 66*000

23 109H u o

j %.8 —Eg ~> -V

1107.

ii (a’)muet+lomle pressure??atlo.

-

~r’

.-

.

.

. . *.

.

.

Figure I.& -

Fuel-air ratio(o) Codnbuetion-ohamber-inletMaoh number.

Perf%manoe owes for flame holder 10. Gutter widthi9.60 inoheet blookefl area, 60.0 peroedh

.

IOWA RM E50H21

.

53

.

.

,

1%!00,‘- l._l I Injeotion Altitude.-

t1110 b 40,000

“- Iloo

I IJugooo

-~ I 1.1 56,000/ -

,

II -n~wl-” I I800 I

600\ I p’- Anmuar lean blow-t I I I I I(d) Combustion-ohamber-outletpremmre and blow-out limlts.

(e) Gas-flowfaotor.

F1.00

●80>v

.60 ~ * *

.40..●02 .03 .04 ●06 .06 ●m

Fuel-a3r ratio

(f) Ctit%= effiolenoy.

Figure I& - ConoludecL Performanceourveo for flame holder 10. Gutterwidth, 2.50 Imhea; blooked area, 60.0 peroent.

54 d-w ~ .- IVACARM E50H21

1

1

,

Blookedarea

(peroent)

-----60 to 62—40.6 to 46

.0

..

-. .-

.8

●

7“a) Fuel-airratio, 0.05; c-stion-ohamber-outlet totalpressure P4, 1600 pouIMs per square foot absolute.

,.0‘.-

.0

,6.1.0 1.4 1.0 %.a 2.6

Clutterwldthg in.

(b) Phel-alr ratio, 0.06j oasbustlon-mer-mtlet totalpressure P4, 2000 pmnds per sqpare foot absolute.

Iilgure16. - Effeot of gutterwldti on oom@ustioneffioienoy.

r

_—.-

b

..,.-

.

.

.

.

.

.

N40A RM E50H21

Gutter width(in. )

1*O-----1.38 to 1.5—.— 2.0

●

100

—- .— -.—

.8

,6.4.

(a) Fuel-airratio, 0.05; mmbustion-ohamber-outlettotalpressure PA, 1800 pounds per squarefoot absolute.

55

*9U

— -——. .—

.0

.6 I

-“40 44 48 # 62 66 60 64Blookedarea, peroent

(b) Pueldir ratio, 0.06, mmbustion-oMmber-outlet totalpressure P4, 2000 P-S per square foot absolute.

P@ure 17. -Effech of blocked wea on mnibustloneffloieney.* . .- ;-—a. -.*.--

.

NAM RM E50H21

.

&

, Flame● i?4‘

A4

.Q~-V5

h 10

~ “m ‘Annu&ar

~blow-out

A

* ●W3

+

#Io

j’.16 ~?

!’ ‘ ‘

n

~.14

~u:;f)lnl

II v

s ● le ‘ blow-outv

*\

.10.

.06..08. ●OS - .04 .06 “.06. .07 ●06

Blow-out fuel-alr ratio(a) (Xambuatlcg&hambe&tlet tothl pressure. P4, 1400 pounds per

aquaro foot absolu,te.

Figure 180 - Oarrelatim of blow-outtits.

*

,.. =.-

8

‘Q

.

.

I’UCARM E5CIE21. 57

(b) Combuetlon+hberatlet total presml?e ?4, ~m pouuds persquare foot absolute.

Figure 18. . Conoluded. sorrel.ation of blow-outdata.

* *NACA-hWW -11-6-60- 476

NAM ml E50H21

#

60

60

40

30

,

Ocaubuetim-ohamber-outlet

*emperatuneT5(’%)

Lcc4nbustimleffioienq, q

00

— —

L/ ‘// ~ o

— — — lmo— ~ ~ . — . .

— . — — — — — — —

1

0 .02 .04 ●06 - .08. 140Fue14ir ratio

Figure 19. - Relaticms betweenwarlous oanbustlm parameters forInlet temperature d 710° R.

,.

.

. .- .=-iii&a

. .