RESEARCHMEMORANDUM

EFFECT ANGLE OF ATTACK AND EXIT NOZZLE

THE PERFORWCE OF A 16-INCHRAM JET A’I

By Eugene

NUMBERS FROM 1.5TO 2.0

Perchonok,FredWilcox,andDonald

LewisFlightPropulsionLaboratoryCleveland,Ohio

I

DESIGN

MACH

Pennington

TMs&xuIcmtccu$wlsClu3slssedInfOrmamcamectlugtimmKamlDsksaofh mid StatasWtthulb~~~BsPhEs’cAct,uscSQSlti32.mhansmi6sbnortimmhtbnofiLYcatenhtnqmmmrtom wntimiztipermn lapmldldki @ saw.Inf4rmmtfonm Chsssned mbtrqutaddpbw-in Smmmtuya rdnmllsmvtcesoftb United

states,qprqrlate clv211mOmcarn ad amplOyeM Of Km l%dmal av4mnlmnt Wta tam a l@nLub lntomt~*~b MM SbkCfMtitibWti ti-wbdmtiW&btir-~

NATIONAL ADVISORY COMMITTEEFOR AERONAUTICS

WASHINGTONOctober5, 1951

—

.

hi ~..:-- .-~*r-=“.

ADVISORYCOMMITTEEFORAERONAUTICS

1.

NACARME51G26 -

NATIONAL.

REEWA.ENHMEMORANDUM

EFFECTOFANGLEOFAT!CAC!KANDEXITNOZZLEDESIGNONTEE

PERFORMANCEOFA 16-INCHRAMJETAT MACHNMBERS

FROM1.5TO 2.0

ByEugenePerchonok,FredWilcox,andDonaldP.ennington

SUMMARY

I An investigationof theperformanceof a 16-inchremjetenginehavinga singleoblique-shockall-external.compressioninletdesignedfora flightMachnumberof1.8,~ conductedin theNKA Lewis8-by6-footsupersonictindtunnel.DatawereobtainedatMachnurib&sfrom1.5to 2.0andanglesofattackfrom0° to10°. Three=dt nozzleswereused;a cylindricaletiensionof thecodx@ion chamber,a 4° hslf-angleconvergingnozzlewitha 0.71contractionratio,anda converging-divergingnozzlehavinga 0.71contractionratioplusre-expsnsiontoessentiallymajorbodyC+meter.

.... .,,#Operationatangle.ofattackof10°causeda r~~ction= c~ustion

efficiencyof about10p&%c&rtsgepointsfromthevalueobtainedat 0°angleof attackandalsocausedreductionsindiffuserpressurerecoveryandairmassflow.At a givencombustion-chsnibertotal-temperatureratiqtherewasa smalldecrementofthethrustcomponentintheflightdirect-ionanda largeincreaseiQ thethrustcomponentintheliftdirectionastheangleof attackwasincreasedfrom0°to10°.

.

.

Withtheburnerconfigurationemployed,thecold-flow.subcriticaldiffuserpulsationsweredsmrpedto verylowamplitudesbyburning.Also,therewassomeevidencethattheexternslenginebodydragwiththeconvergingexitnozzledecreasedbelowthecold-flowvalueas theexhaust-gsatemperaturewasraised.

~ engineefficiencieswereobtainedwiththeconverging-divergingexit-nozzleconfiguration.Graphiteservedasa satisfactorymaterialforthisnozzle.

\

2● -...-.”

INTRODUCTION-

* NACARM E51G26

,. .._

.

.

An experimentalinvestigationoftheperformanceof a 16-inchramjet,enginewasconductedin-theNACALewislaboratory8-by 6-footsupersonicwindtunnel.Theengine,whichhada singleoblique-shockall-externalcompressioninletwasdesignedfora flightMachnumber

N..

of1.8. Engineperformancewitha constant-areaexitnozzleat0°a@e E.ofattackispresentedinreference1. Dataarenowavailableat anglesof attackfrom0°to10°andwithtwoadditionalexit-nozzleconfigura-tions,a eonicslconvergingnozzleanda converging-divergingnozzle.

Effectsofangleof attackoninternalengineperformance&d acomparisonofoperationandperformanceforthethreedifferentexit-nozzleconfigurationsarepresentedanddiscussed.Thesubcriticaldiffuserflow”stabilityunderbothcold-flowandburningconditionsisslsoevaluated.DataarepresentedatMachnumbersfrom1.5to 2.0andforReynoldsnumbers(basedonengineleuth)from77.5to 81.1x106.

Theconverging-divergingnozzleinsertwasfabricatedofgraphite,anditsdurabil~ty-a&dwe& undertypicaldiscussed.

APPARATUS

op&ratingconditionsme

Theengineandburnerconfigurationand&e tunnelinstallationwerethessmeasdescribedinreference1. A schematicdiegrsmoftheengineisshowninfigure1 anda detailedtabulationof enginecoordi-natesisgivenintableI. Alsoindicatedinfigure1 aredetailsofthestaticandtotsl-pressuresurveysat stations2 andx. Theinletwasdesignedsothatata streamMachnumber~ of1.8theshockgeneratedby the50°conicalspikewouldfallslightlyaheadofthecowllip. Thecombustionchamberwas16 inchesindiameter.

.

.

Tl&eee~dt-nozzleconfigurationswereinvestigated,a constantareanozzle,a convergingnozzle,anda converging-divergingnozzle.Theover-allenginelengthfmm spiketiptonozzleexitwasthe.sameforallthreeconfigurations,16 feet.Theconvergingnozzlewasconicalwitha convergencehalfangleof4° anda ratioofexitsreato combustion- :chamberareaof0.71.Theconverging-divergingnozzlealsohada ratioofthroatsreato combustionchamberareaof 0.71s@ thenre-expandedtoessentiallycombustionchamberdiameter.Thisnozzleconsistedofagraphiteinsertandits,contourandretainingdetailswe indicatedinfigure2. .

A schematicdiagramof-theflsmeholder,fuel”manifold,andspraynozzle.srrangementisgiveninfigure3. Theflsme-holderstifaceopenareawas133percentof thecombustion-chamberfrontalarea.

.Propylene

,. ->.. _.. , .— —

NACAF?ME51G26 3.

. oxidewasusedasfuel. Thevortex-typepilotburnerwasoperatedwith. a blendof 50-percentgasolineand50-percentpropyleneoxideby volume.

g An independentlysupportedwater-cooledtailrakewasusedto(u measuretheexitmomentumat anglesof attackof 0° and6°forsllbut

thegralhitenozzle.Staticwallorificeswerelocatedslongthefore ‘sectionofthediffuseroutershellandalongthediffuserinnerwallsndcenterbody. Fluctuationsinpressureloadson theoutershellandinternallyatthediffuserexitweredeterminedwithcommercialdifferential-pressurepickups.

Thetotsltemperaturesadpressurein thetestsectiondependedon thestresmMachnumberaswellas atmosphericconditionsendcould ,

notbe independentlycontrolled.

SYM80LS

Thefollowingsymbolswe usedinthisreport:

.

.

A

c

(et-~d)

‘%P

F

Ft

(l?t-F’d)Vo~hW#

fja

h

J

sxea(sqft)

areaonwhichsllcoefficientsarebased(areaof 16 in.diametercircle)

forcecoefficient,—&nex

propulsivethrustcoefficient

P-POstaticpressurecoefficient,%

force(lb)

netinternal.thrust(lb)

reducedengine

fuel-airratio

efficiency(percent)

lowerheatingvslueoffuel(13,075Btu/lbforpropyleneoxide]

mechanicalequivalent.ofheat(778Btu/ftlb)

.*.

.,

—.

4

M

m

M/q

.

Subscripts:

NACARME51G26

Machnumber

massflow(slugs/see)

massflowratio,ratioofenginetothemassflowhatinga diameterequsJ-

.

. .

.

theactualairmassflowthroughcontainedinfree-stresmtubetodiffuser-inletdismeter $

tots3pressure(lb/sqftabsolute)

staticpressure(lb/sqft absolute)

maximumpressureamplitudecoefficient,- minimumpressure -r-—

averagepressure

()dw~c pressure* P ~2

radius(in.)

statictemperature,

velocity(ft/see)

fuelflow(lb/see).

@e ofattack(deg)

ratioof specificheats

combustionefficiency .

total-temperatureratioacrossengine

a airenteringengine, ,.

d totalexternalbodydrag

H componentofnetthrustinflighttirection

il. jetthrust

t netinternalthrust

v componeritafnetthrustinliftdirection

a

.,.

–..=—

.

NACAF?ME51G26.

x a& rlOwmeasuringstation(59in.fromcowllip)d

o freestresm

1 engineinlet

5

2 alternateairflowmeasuringstation(18in.fromcowllip)

3 combustionchsaiberinlet

4 nozzleinlet

6 nozzleexit

PROCEDURE

A cold-flowinvestigationsimilarto thatofreference1 wasmadewiththeconvergingnozzleto determinetheeffectonexternalbodydragofboattailingtheexitnozzle.As inreference1, a dummystrutwasemployedto separateexternslbodydragfromthetotaldragmeasuredby thetunnelbslance.Theflameholderwaaremovedanda remotely

. adjustablevalveinsertedatthecotiustionch~er inlettovarythetiffuserexitMachnumberoverbotht~esubcriticalandsupercriticslflowranges..

Themassairflowthroughtheenginereportedhereinwascomputedfrompressuredataobtainedat stationx (seefig.1) andon thebasisof additionalindependentairflowmeasurementsis consideredaccurateto*3 percent.Thediffuserpressurerecoveryis alsobasedonpressuresmeasuredatthisstationbecauseat0°,angleof attackthetotalpressureatstation3, thecombustionchsniberinlet,wasfoundtobe thesameas thatat stationx withintheaccuracyof themeasurement.Theburner-inletMachnumbersM3 arebasedon theannularareaatthediffuserexit,station3.

Jetthrustsforthecold-flowinvestigationweredeterminedfromthemeasuredairflow,twostaticwalJorificesatthenozzleexit,enda total-pressurerakelocatedjustinsideofthenozzleexit. Withconibustion,theconstant-sreaandconvergingnozzleswereassumedchokedattheexitandthejetthrustwascomputedfromthetail-raketotal.-pressuredata.Foranglesof attackgreaterthan6°however,thewater-cooledtailrakecouldnotbe usedandothermeanswererequiredtoobtaintheAt totalpressure.Foreachexitconfigurationthesame

. relationwasdeterminedto existbetween~ -d theratioofnozzleexittot~ pressuretototalpressureat stationx p6/px forboth0° and6°angleof attack.Thissamerelatiohbetween~. and p6/pxwasassumedat10°,and PC couldthenbe determinedfromthevaluesof M3 and Px.

“

6* &ii .,

Thewater-cooledtailrs.kewasnotusedconverging-divergingexitnozzle.Sincethe

NACARME51G26● —

duringtestswiththechokingcross-sectional u_

areasforboththeconvergentandtheconvergent-divergentnozzleswereequsl,theflowthroughthedivergentsectionofthelatternozzlewas ‘assumedtobe isentropic,-andtheconvergentnozzledatawaathenused Nto evsluatetheexitgastem~eraturefortheconvergent-divergentnozzle.Thenetpropulsivethrustwasdeterminedby addingthesupportstrut if

dragto thebalancereadingandthenetinternalthrustobtainedbyaddingthepropulsivethrustvaluetothetotal.cold-flowexternalbodydrag.

Thecombustionefficiency,definedastheratioof thechangeinenergyofthegasesflowingthroughtheengineto thelowerheatingvalueofthefuelinjected,andallotherinternalengineperformanceparameterswerecomputedby themethodsgenersllyemployedandoutlinedinreferences2 and3. Neitherthecombustionefficiencynorthet&al-temperatureratioacrosstheenginewerecorrectedforcodinglosses.

Thequantitiescomputedfrotipressureinstrumentationwereassumedtorepresenta validtimeaverageoftheactualvalueduringpulsingoperation(seereference4).

—

.RESULTSAND~DISCUSSION

Effectofhgle ofAttack

Diffuserpressurerecovery.- Subcriticalandsupercriticaldiffuserperformancedataerepresentedinfigure4 for ~ valuesof1.5,1.8,“and2.0-andanglesof attackof0°,6°,and10°forbothcold-flowandburningconditions.Nomeasurableeffectofburningondiffusertotal-pressurerecoverywasobserved.Bdh thediffuserpressurerecoveryandtheairmassflowdecressedastheangleof attackwasprogressivelyincreasedfrom@ to10°. FortheMachnumbersinvesti-gated,thereductioninmassflowwasbetween3 and4 percent.Ingeneral.,thesensitivityofpressurerecoveryandairmassflowtochangesinangleofattackincreasedbothwithangleofattackand Mo.Theseresultsareconsistentwithpreviouslypublisheddata(reference5).

Theeffectof angleofattackonthecriticalI@,isnotreadilypredictable,foritdependsnotonlyonthedecreasein airflowbutonthedropin criticalpressurerecoveryaswell.Fora pressurelossamountingto severalpercent,Mo = 1.8and2.0,thecriticalM3increasedslightlyastheangleofattackwasraised.At Mo= 1.5thepressurelosswaslittlemorethsm1 percentandthecriticelM3wasreducedbecauseofa “decreasein airflow.

d–

.

.

.

NAC!ARM E51G26

Diffuserpulsing.-at MO of1.8and2.0.

7

SubcriticaldiffuserinstabilitywasobservedThisinstabilitycausesperiodicfluctuations

inthediffuserstaticandtotalpressures.Thefrequencyof thesepulsesisthesamethroughoutthediffuser,butthesmplitudedependsonthelocationatwhichthemeasurementismade.As a typi.cslexampleoftheeffectofoperatingconditionon suchfluctuations,thecold-flawfrequencysndsmplitudevsriationof thestaticpressureatthediffuserexitarepresentedfor0° sngleofattackinfigure5. Theemplitudeofthefluctuationis expressedin coefficientformaE ~ wh~e & is .

thedifferencebetweentheaveragemsximumandtheaverageminimumpressuresand p isthemeanpressureat thepointofmeasurement.

Forthetwocasesillustrated,pulsingwasfirstencounterednearthecriticalM3 vslue,andonceinitiatedtheamplitudeofthepulseincreasedshsrplyas ~ waslowered.At sn M3 of approhtelyO.11,smplitudecoefficientsoftheorderof 0.8(representingpressurefluctuationsof~7.4lb/sqin.)wereobserved.FurtherreductionsofMS resultedina reversalintrendamda dropin smplitude.Althoughit isnottoowelldefinedby thesedata,thereisalsoa trendtowardreducedamplitudesas Mo islowered.Littlechangeinamplitudewasobtainedwhentheangleof attackwaschsngedfrom0°to 6°butwhenitwasincreasedfrom6°to10°,thecold-flowamplitudeswerereducedconsiderably.

Oncepulsingwasestablished,thefrequenciesatboth Mo = 1.8 .snd2.0wereessentiallysimilar.Thisresultis consistentwiththetheoryofreference6 andisdueprimarilytosimilarlyshapedpressurerecoverycurvesatbothMachnunibers.A theoreticalfrequencycurve,basedon thetheoryofreference6,is shownfor Mo= 2.0andgoodagreementwithexperimentisobservedfromtheinceptionofpulsingto I@= 0.15.Althoughbelowthisvaluethetrendsbetweentheoryandexperimentaresimilsr,e~erimental.frequenciesup to 3 cyclespersecondhigherthanpredictedwereobserved.

Thecombinedeffectofinsertinga flameholderandburningonfrequencyandamplitude,bothonthecowlandtiternallyatthediffuserexit,areshowninfigure6. Thesedataarefor Mo = 1.8,andsimilsrresultswereobtainedat Mo = 2.0. Forconveniencein interpretingthedata,thestaticpressurecoefficientsCp at thepointsofmeasure-mentsrealsoindicated.Staticpressurefluctuationsontheexternslcowlsurfaceweremeasuredat45°fromtopcenterand1.47bodydismetersfromthecowllip. Thedynamicpressurepickupwithwhichthismeasme-mentwasmadewasmountedinthecenterbodyandconnectedto thecowl

. surfacewitha l/4-inchtube.

Externslandinternslpressurefluctuationsoccurredinitiallyat. thesame m value@ hadidenticalfrequencies.Thesmplitude

8 &Ad&wQ=His NACARME51G26

coefficientsandthepressureamplitudeswere,however,considerablylessexternallythaninternally.Considerablygreateramplitudesandfluctu-atingpressure10.wIswillundoubtedlybe observedatexternslstationsclosertotheinlet-lip.At 10°angleofattack,randomexternal

‘3poundspersquareinch(tentimesthemsximumpressurepulsationsof -valueat0°angle’ofattack)wereobserved.

Thepulsationfrequencycouldnotbe readilyevaluatedunderburningconditionsbecausecombustionpulsationsweresuperimposedonthediffuserpulsation,causingthepressuretracesobtainedtobe quiteirregularundersupercriticslEMwellassubcriticalflowconditions.Thecombinedeffectofinsertingtheflameholderandburningwastodampenconsiderablytheamplitudeof thecold-flowsubcriticaldiffuserpulse.At&= 0.145,theamplitudecoefficientofthediffuser-exitstaticpressurewasreducedfroma cold-flowvalueof0.45toa burningvaluebelow0.04.Thislattercoefficientcorrespondstoa pressurevariationof*0.72poundspersquareinch.

Thedsmpinginfluenceexertedunderburningconditionsextendedtotheexternalpressurefluctuationsaswell..Theaboveaverageamplitudesofthefiveconditionsindicatedonfigure6 aredueto “irregularrandomdisturbancesandnottosubcriticaldiffuserinstability.

Onlythecombineddampingeffectivenessoftheflameholderandburningwasobteined.Theresultsobtainedmaythereforebe peculiarto.theburnerconfigurationinvestigatedaqdotherconfigurationsmayaqplifythe,pulse,causingcombustorblow-out.

Typicalpressuretracesundersubcriticalandsupercriticslflowconditionsarepresentedinfigures7 and8,respectively.8ubcritically,a regularpulsationwasobservedinthecold-flowcase,whereasthecombustionpulsewassuperimposedonthispatternintheSupercritically,lowamplitudeirregularpulsesoccurredbothatthediffuserexitandonthecowlstiface.At afrequencyatismplitudecoefficientatthe&l.ffuserexitmatel.ythessmeforboth0° and6° angleofattack.

burningcase.duringburninggivenM3 thewereapproxi-

To indicatethenormalshocktravelfora typicalsubcriticaloperatingcondition,a sequencefroma high-speedmotionpictureofthecold-flowshockmovementatthecowlinletfor Mo= 2.0,a =-6°,anda massflowratiom/mo of0.784isshowninfigure9.

Rressuredistribution.- Thelongitudinal.variationwithmassflowandstresmMachnumberofthestaticpressurealongtheuppersurfaceofthecenterbodyandtheexternalstaticpressurealongthetopsurfaceofthecowleregivenfor0° angleof attackinfigure10(a).Thepressuredistributionsonthe.internalsurfaceofthecowlwereessen-tiallythesaneas’thoseonthecenterbody”andthereforearenotpresented. . . ..-. .

b

.

.

N

F

.=

.

— —

-.

.n ..-

.- .-

kWfi=@m& ‘-””

.

2 MCARME51G26●

Theeffectofms flowratioontheexteyneJ-

9

cowlpressurecoef-. ficientbeyond0.8bbdydiemeterfromthelipwassmellendappesrsto

be independentof stresmMachnumber.Intheregionbetween.thelipand0.8bodytiameter,thevaluesof ~ decremeas thems flow

2N ratioisreduceduntilathighspillageratiosCp becomesnegativeN andleadlng-edgesuctionoccurs.Theincreasein ~ at 3 body

diametersfromthelipfor Mo = 1.5wascausedby reflectionfromthetunnelwsXlsoftheinletshockdisturbance.

Undersupercriticalflowconditions,a smallcontractionat theinletcausedanappreciablesupersonicflowdecelerationin theregionbetweenthecowllipand0.1bodydiameterat Mo = 2. Theflowthenreacceleratesuntila normslshockoccurs.Becausethebounderylayerc=ot supportan abruptpessu rise)a branchedshod CO~iWatiOnis indicatedby thepressurecoefficients.Itwould,therefore,bedifficulttu usea controlmechanismdesignedto sensethenormalshockpositionfromstaticwallpressure.Theirregularityinthepressuredistributionsfrom1 to 1.5hcdydiametersat themaximmnM3 conditionisthoughttobe dueto thecenter-bodysupportstruts.

.

.

Theeffectof angleofattackand Mo on thepressuredistributionalongthetopand’bottomsurfacesof thecowlforcritic-inlet”flowisshowninfigure10(b).At allthreevsluesof Mo,considerableliftresultedasthebodywasraisedtopositiveanglesof at”tack.At agivenMachnumberendangleof attack,thepressurecoefficientsonbothtopandbottomsurfaceswereessentiallyconstantbetween1.5and3.2bodydiemetersfromthelip. Datawerenottakenbeyondthislatterposition.Similarresultshavebeenobtainedonbodiesapproximately= thissize(reference5).

Thevariationofthestaticpressuresontheupperandlowersurfacesofthecenterbodywith Mo end@e of attackis showninfigure10(c).Onbothsurfaces,theangleof attackeffectsincreasewith M.o.Thedifferencesinpressurebetweenthetopandbottomsurfacessreespeciallyapparentat thelowest~ ad occurintheregionbetweenthelipand0.5bodydismeterfromthelip. At thehighervaluesof Mo,somedifferenceoccursin theregionofthecenter-bodysupportstrut.Theconclusionisreachedthatforanglesof attackbetween0° and10°,internalforcesnormsltotheengineaxissreingeneralexperiencedintheregtonofthediffuserin+et.

Internalvelocitydistribution.- Representativedataof thelocalMachnumbervariationattheair-flowmeasuringstation,sreshowninfigureH for ~ = 1.8. The,ssmetrendsandessenti~ythesame .velocityprofileswerenotedunderbothcold-flowandburningconditions,figuresn(a) andll(b).An essentiallyuniformcircumferentialvelocitydistributionresultedat0°angleof attack.As theengleof attac&was

. ..

10

increased,littleeffectannularductbuta shift

--ma” ‘“ NACARME51G26●

ontheflowwasnotedintheupperhalfoftheinthepeakvelocitiestowardthecenterbody.

—

wasobservedin thelowerhalfoftheduct;-Similsrresultswereobtainedsubcritically,exceptthattheprofilesintheupperhslfoftheductweresomewhatflatteratanglesof attackgreaterthan0°thsmthesupercriticaldatashown.

Theeffectof I@ onthevelocitydistributionisdemonstratedinfigure11(c).Thepeakvelocitiesconcentratenearthecenterbody

, forsubcriticalflowandmovetowsrdtheouterwti aatheflowbecomessupercriticsl.Thissametrendhasalsobeeriobservedwithanengineofdifferentdesign(reference4).

Combustorperformance.- Combustor@rfozmancewitha constant-areaoutletat B@= 1.8ispresentedastypicalof theeffectof angleofattackonb~ner operationinfigure12. Increasingtheangleofattackfrom0°to10°decreasedthepeaktemperatureratioz from4,6to4.3,butdidnotnoticeablychangetheotherburtiroperatingcharacteristics.Thisreductionisthoughttobe causedbythechsmgeinfuel-airdistributionatthecombustionchsmberinlet.Theoperablefuel-airratiorangewaslimitedby thefuelsystemratherthanburnerblow-out,andtheburnerwasoperatedsatisfactorilyto10°angleof attackfroma valueof ~ aalowas 0.18toaahighas 0.32withoutinstabilityorundueshellheating.Withpropyleneoxideasfuel,ignitionwasobtainedat10°@e of attackaaeasilyasat 0°,andfortheconfigu-rationinvestigatedno additionalburnerproblemswereintroducedbyoperationatanglesof attackto10°.

Internal engine_performarrce.- Thetypicaleffectof angleofattackoninternslengineperformanceis shownintermsof thejetthrustcoefficientfor ~ = 1.8,figure13. Thedecreasein exitjetthrustata givenT snd Mo astheangleof attackisincreasedresultsfrdmtwosimultaneouseffects,a reductionindiffuserpressurerecoveryanda dropinthemasssirflowthrc)ughtheengine.IntieMo rangeinvestigated,thereductionin jetT_thrustcoefficientastheangle.ofattackwasincreasedappearedindependentof T andwasdueprimarilytothereductioniiairflow.

Theeffectofangleof attackcanbemorereadilyinterpretedifthenetinternslengineforcesme presentedin termsoftheflightandliftdirections.Thehorizontal(flightdirection)nettiternalthrustcoefficientCH isbasedon a thrustvaluecomputedfromthefollowingequation

,FH=Fjcosu-~Vo

andthevsrticd(lift)componentCv basedona thrustcomputedfromFV= Fj sins-”

.

.-

—

.—

.

*

NACARM E51G26 11

.Thechangein ~ and Cv with Mo,T, andangleof attackis

sh~wninfigure14. Althoughthespecificdatapresentedwereobtainedtiththeconstantsreaexitnozzle,similartrendswereobservedwiththeothernozzleconfigurationsinvestigated.By operati~”theengineatpositiveanglesof attack,considerableliftcanbe derivedfrominternalforceswithonlya smalll.lossin FH. Forexample,whentheangleof attackwasincreasedfromQ0 to10°,reductionsin CE raUg-ingfrom7 to15 percentoccurred;.however,at10°amgleof.attackCvvsluesintheorderof30 to50percentof ~ wereobtained.Thus>asa resultof internalforcesonly,incrementalliftto thrustratiosasgreatas5 wereattained.

. .At positiveanglesof attack,a sizeableliftis obtainednotonly

fromtheverticalcomponentoftheinternalengineforcesbutfromthe ,externalaerod~ami.cforceson theenginebodyaswell. Apartfromstabilityconsiderationsandchangesin coribustionefficiency,thedesirabilityofflyinga ramjetatpositiveanglesof attackisdeter-minedlyweighingtheincreaseinbodydragandthereductionin FHsgainsttheliftachievedandthereductionintherequiredwingareawhichresults.Theanalysisofreference7 indicatesthattherangeof a ramjet-poweredvehiclemaybe increasedbymaintainingtheengineat a positiveangleof attack.

.

EffectofExitNozzleConfigurationonEnginePerformance

Externalbodydrag.- Body-dragcoefficientsfor Mo vsluesfrom1.5to2.0,giveninreference1 fortheconstszrt-sreaexitnozzleengineconfiguration,arereproducedin figure15. Thelineofmaximummassflowratiorepresentstheminimumexternalbodydragateach ~,andthesameminimumdragcoefficientwasobservedunderbothcold-flowandburningconditions.Thedashedlineon figure15representstheminimumexternaldragof theconvergingexit-nozzleengineconfigurationandwasobtainedby addingthetheoreticalboattaildragto themin-drsgcurveof thestraight-pipeconfiguration.Becauseof thelowboattailangle,identicalvaluesforboattaildragswerecomputedfromlinearizedtheoryandby themethodof characteristics.Theexperi-mentalminimumbodydragsundercold-flowconditionsfellslightlybelowthetheoreticalvalues.

Thesupercriticalextern@bodydragwitha conicalconvergingexitnozzle,determinedunderburningconditions,indicatesa considerablereductioninbodydragoverthatobtainedundercold-flowconditions,figure16. Themagnitudeof thisreductionincreasedwithboth B@ andz. At Mo= 2 and %=.3.6,a reductionszuountingto45percentofthesupercriticslcold-flowdragwasobserved.

12 NACARME51G26

Additionalindependentverificationofthisphenomenoncouldnot ;be obtainedwiththelimitedmeasurementsmade. However,becausetheobserveddragreductionexceedsthelimitationsof experimentalaccuracyitis“thought.thattheconvergingnozzleactuallyissubjecttoincreas-ingexternalpressuresas thetemperatureofthejetiSrafsed.Asimilsrdragreductionhasalsobeenobservedinwindtunneltestsofa smallburningrsmjetmodel(reference8).

Coldjetsexhaustingfroma bodywithboattailanda relativelysmsllamountofboundsxylayerhavereducedthesupersonicexternalbodydragbelowthatforthejet~offcondition,(references9 end10).Accordingtothesedata,thedecreaseinbeg atPressureratioss~l~tothoseof thisinvestigationwouldbe negligible.Yetithasbeenobservedduringthisinvestigationandinothers(references11 and12)thatboattailedbodydragswitha hotjetarenoticeablylessthanthe ‘jet-offor cold-jetcondition.Withburning,heattransferthroughthewellof thecombustionchembercanthickentheexternalboundarylayer;butthefactthata changeindrsgdidnotoccurwiththeconstant-areaexitnegatesthepossibilityof a frictiondrageffect.Thephenomenonmaybe a tunnel-modelinterferenceeffect.Othermechanismswhichcouldalsocausethisdragreductionsrediscussedinreference13.

Netinternalthrust.- TheeffectofexitnozzleconfigurationonthenetinternslthrustcoefficientCt isshowninfigure17 aaafunctionof’I@ for ~ = 1.5,1.8,and2.0. Thedatafornozzlecontractionratios% -ofo.’71

zand1.0arebasedontail-rakemeasure-

ments,whereastheconverging-divergingnozzledatawerecomputedfrtibslancemeasurementsan anetiernslbodydragtskenasequaltothe

icoldflowdragofthet= 1“0Cotiiwration”‘e ‘heoreticdnet

internaLthrustoftheconverging-divergingoutletwasdetermined.byA6addingtothe%

= 0.71datathethrustincr=entduetoi.sentropic

expansioninthedivergingnozzlesection.Sincetheexperimentaldatafallshovethetheoreticalcurves,itis concludedthateithertheflowthroughthedivergingsectionofthe’nozzleisnotisentropicorthethroatareasinthetwocases=e notidentical.(A2 percentdifferericeint&oat_sreacouldcausethisapparentdiscrepancy.)In anycase,atall I@ vs&es investigatedtheconverging-divergingoutletgaveaconsistentanddefi,niteadvantageovera conicalconvergingoutlethavingthessmegeometricthroatarea.

Thenetinternalthrustcoefficientsincreaseinboththesub-criticalandthesupercriticalregionsas thevalueof I@ islow5redby raisingthetotal-temperatureratio‘c.However,a breakinthecurveoccursatthecriticalflowcondition.At a givenM3,meximm

.

--

~

.-—

.-

—-

-—.

.-

—

.

.

.

wrw~ “’

NACARM E51G26 13

internalthrustswereobtainedwiththe A6T

becausetheenginewasbeingoperatedatthethemaximumexperimentalnetinternslthrust

d+ converging-divergingnozzle,Ct=zbw Mo = 1.8,thewidestnetinternal

MachnumbersresultedfortheA6G

Conibustionefficiency.- Theon combustionchaniberperformancesentedfor0° angleof.attackand

= 1.0configuration,hi@est’% va&e. Althoughwssobtainedwiththe

0.85at Mo =.2.0and0.84atthrustcoefficientrangeatd-lstresm “= 1.0configuration.

effect-ofthevariousexhaustnozzlesis shownin figure18. .Dataarepre-ata stresmMachnumberof1.8only.

forin geners3t~esetrendsaretypical.ofthoseobtsinedat theothe>anglesof attackand Mo valuesinvestigated.Thefuel-airratiorangeforeachco@igurationisnotsi@ficant,fortherewasnoleanblow-outlimitandtherichlimitwasagaindependentonthemaximumpumpingcapacityofthefuelsystem.(Stoichiometricfuel-airratioforpropyleneoxideis 0.105.)

As expected,essentisI1.ysimilarconibustorperformancewasobservedfortheconvergingandtheconverging-d3.verg@gnozzleconfigurations.Thesmelldifferencein conibustionefficiencywhichwasobservedis

. withintheaccuracyofthedata. Thereissomeetidence,however,thattheflowthroughthedivergingsectionisnoti.sentropic,andif com-bustionis consideredtooccurin thedivergingsection,thedifference. betweenthetwocurveswiIlbe reduced.

Netengineperformance.- Inorderto obtaina bettercomparisonofnozzleconfigurationsforrangeconsiderations,theexternaldragsmustalsobe considered.Thiscanbe doneby presentingthereducedengineefficiencyintermsofthepropulsivethrustcoefficient(Ct-Cd),figme 19..Theengineefficiencyisbasicellythereciprocsllofthethrustspecfiicfuelconsumptionandhasbeenreducedforconvenienceto100percentcombustionefficiencytoeliminatean additionalvariable.Thevaluesof M3 ad % sreslsopresentedto sldanalysisandinter-pretationofthe data.

Overtherangeinvestigated,theresultsindicatethatfora given45propulsivethrustthe — = 0.71outletismoreefficientthsnthe&

.

&—= 1.0outlet.(The ‘64

= 1.0dataweretskenfromreference1.)G’

Moreover,addl.tionalgsinresultsif an internally&pandingsectionisaddedatthenozzleoutlet.A% &= 2.o, a maximumreducedengine- .,efficiencyof 21percentsada msximumpropulsivethrustcoefficientof0.68wereachieved.EYogressivelylowervaluesresultedas ~ was

. reduced.#

14 NAcARM E51G26.

Becausethereis somequestionconcerningthetruedragoftheconverging-nozzleconfiguration.whileburning,thecold-flowdragvalueswereusedin computingthed~t~pointsplottedinfigure19. I.fthebodydragdeterminedunderburningconditionsisusedinstead,thegti-hresultingwiththeconverging-divergingnozzleis slight.To showthiseffect,thevariationof engineefficiency,basedonburningdragti,hasslsobeenimcludedinfigure19.

Whenthetotal-temperatureratioisincreasedtothepointwherewitha fixedgeotietryoutletthe-flowbecomessubcritical,thetotslexternalbodydragincreasesandthediffusertotal-~essurerecoverygenerallyfalls.Althoughthiscombinatiofiof circumstancespermitscontinuedincreasesinthepropulsivethrust,itultimatelyresultsina red;ctionintheengineefficiency.Sucha trendisappsrentfor

.—=” 0.71configurationat ~ = 1.8&d 1.5where,although’‘he A;

(Ct-cdjcontinuedtiOincrease@th z, the.risingfuel-consumptionratecauseda reductioninengineefficiency.

Theengine-ispotentiallycapableof&eaterpropulsivethrustswitha constant-areanozzlethanwitha contractedoutlet.Ifthe(Ct-Cd)dataisplottedasa functionof J& fortheseveralnozzleconfigurationsinvestigated,(fig.20),themagnitudeofthepropulsivethrustdifferencesismorereadily”appuqnt.””Thegreaterpropulsivethrustsdevelopedtiththeuncontractedoutletisduetothehigher‘rvsluesrequiredtomaintaina giveninletflowcondition.

DurabilityofGraphiteNozzle

Inmanysuggestedramjetdesigns,grap~tehasbeenproposed”&sa desirableexitnozzlematerial.However,~littleinfo~tionisavailable-ontheuseanddurabilityofgraputefor”suchap~lications.Theenginewasinitisllyoperatedwitha gr~@itenozzleforabout2c)minutesat ~ = 1.8,2.0;and0°angletiattack.Theenginewasthenrunforapproximately30tinutesat Mo= 2.0,6°and10°anglesofattack,and ~ = 1.6,0°angleofattack(datanotpresented).Duringthesermthe enginewasoperatedove”ra rangeoffuelflowsendthegraphitenozzlewassubjectedtotemperaturessufficientlyhighto causeittoglow.

Inspectionof thegraphiteinsertindicateddo appreciablesurfacewearor deterioration.Temperature-sensitivepaintsindicatedthattheciutersurfaceof theshellin a regionon topcenterandaheadofthegraphitenozzleinserthadreachedllO@ F,,hutthatnopartoftheshellsurrounding‘theinsert”hadreachedthistemperature!Themethodofretainingthegraphitenozzleinsertintheoutershellprovedsatis-factoryandcausednodifficultyinTabricat-i”on.

&..—

Ny.—.

..

.-

-.

“--

.—

.A -

,,

NACARME51G26 15.

- SUMMARYOFRESULTS.

.

.

.

.

Thefollowingresultswereobtainedfroman investigationof a16-inchrsmjetengineintheNACALewislaboratory8-by 6-footsuper-sonictunnel.Datawereobtainedwiththreeexitnozzleconfigurationsat anglesof attackfrom0°to10°andMachnumbers.from1.5to2.0.

1. Fortheburnerconfigurationused,a changein engineangleofattackfrom0°to10°causeda reductionin combustionefficiencyofabout10percentagepointswithnoreductioninrangeof operationoreaseofignition.

2. Somelossesindiffusertotal-pressurerecoveryandmaximummassflowoccurredastheangleof attackkaschangedfrom0°to10°.me etude oftheselossesincreasedwithstreamMachnumberaudangleof attack.Similsrvelocitydistributionsatthediffuserexitandthessmediffuserperformancewereobtainedundercold-flowtidburningconditions.

3. A considerableliftcanbe achievedfrominternalforcesbyoperatingtheengineatpositiveanglesof attackwithonlysmslllossesinhorizontalthrust.

4. Subcriticalpressurefluctuationatthediffuserefitamountingtoasmuchaa27*4poundspersqu&reinchwereobservedundercold-flowconditions.Thesefluctuationsweredsmpedoutintheburningcase,thegreatestsmplitudeobservedbeingabout*0.7poundspersquareinch.Littlechangeinsmplitudewasobservedin thecold-flowcasewhentheangleof attackwasincreasedfrom0°to 6°,butthechsngefrom6°to10°causeda considerablereductioninsmplitude.

5. As predictedby theorythecold-flowenginebodydrsgincreasedslightlywhentheconstant-areaexit-nozzlewasreplacedwitha con-vergingnozzle.Thereis someetidence,however,thattheenginebodydragwitha boat-tailedafterbodymaybe appreciablylessunderburningthancold-flowconditions.

6. Maximumengineefficiencieswereobtainedwitha converging-divergingexitnozzleconfiguration.

7. A grapldteconverging-divergi~exitnozzlewasoperatedforaperiodof50minutesattemperaturessufficientlyhighto causethegraphitetoglow.Thedurabilityoftheinsertprovedsatisfactoryandno crackingorerosionoccurredduringthisperiodofoperation.

LewisFlightPropulsionLaboratoryNationalAdvisoryCommitteeforAeronautics

Cleveland,Ohio

16.

NACARME51G26.

REFERENCES

‘Nussdorf’er}T.,Wilcox,F.,andPerchonok,E.: Investigationat.

1.ZeroAngleofAttackofa 16-InchRsm-JetEnginein8-by 6-FootSupersonicWindTunnel.’NACARME50L04,1950.

2. Perchonok,Eugene,Wilcox,FredA.,andSterbentz,WilliamE.: ~

FlrelimindcyDevelopmentgndPerformanceInvestigationof a 20-Inch ESteady-FlowRsmJet. NACAACRE6D05,1946. .

3. Perchonok,Eugene,Sterbentz,Wi.llismH,,andWilcox,FredA.:Performanceofa 20-InchSteady-FlowRsmJetatHighAltitudesmd Rsm-PressureRatios.NACARME6L06,1947.

4. Perchonok,Eugene,andFarley;JohnM.: Internsl-FlowandBurningCharacteristicsof16-Inch.RamJetOperatingina FreFJetatMachNwibersof1.35and”l.73.NACARME51C16,1951.

5. Esenwein,FredT.,andValerino,AlfredS.: ForceandPressureCharacteristicsfora Series’ofNoseInletsatMachNur?ibersfrom1.59to1.99..I - ConicalSpikeA1l-ExternslCompressionInletwithSubsoniccowlLip- NACARME50J26,1951. .

.6. Sterbentz,WillismH.,andEwsrd,JohnC.: Criterionsfor

PredictionandCohtrolofRam-JetFlowPulsations.NACARM E51C27,1951. .

7. Howard,E.,LuidensjR. W.,andAllen,J.L.: Forceand~essureCh=acteristicsfora SeriesofNoseInletsatMachNumbersfrom1.59to1.99. v - AnalysisandC!czuparisononBasisofRsm-Jet —AircraftRangeand.operationalCharacteristics.NACARM E51G23

..-

8. Singham,J.R.,Pruden,F. W.,andTomlinson,R. C.: TestsonaWorkingModelRsmJetin a SupersonicWindTunnel.Rep.No.R-20,BritishN.G’.T.E.,Nov.1947.

9. Erdmann: Widerstandsbeiwertefb.dasA4VlPmitBerflcksi.chtigung —Qes&mhl - undReibungseinflussesfb Unter-undUberschsJ&eschtindigkeiten-UntersuchungderStrahlexp&sion.Pee~emundeArchivNo.66/105,M&s 24,1943.(Trans.H. P.Liepmsmn,‘GoodyearAircraftCorporation,R-30-18,Part19,Feb..l5,1946.)

10. Love,EugeneS.: AerodynamicInvestigationofa ParabolicBodyofRevolutionatMachNmibersof1.92smdSomeEffectsofanAnnular-JetExhaustingfromtheBase. NACARM L9K09,1950. .

..-.

.

3 NACARM E51G26 17

11. Storiey,WilliamE.,Jr.,andKatz,Ellis:PressureMeasurements.. on a Shs.rply ConvergingFuselageAfterbodywithJetOn sndOff

atMachNumbersfrom0.8to 1.6. NAcA’M L50F06,1950.

12. Edson,J..B.: OpticslStudiesof theJetFltieof theV-2Missile -inmight. Rep.708,BsJlisticRes.Labs.(AberdeenProtingGround,Md.),Oct.1949.

13. Hebrank,W.H.,ad Hicks,B. L.: A PreliminaryStudyof theExternslRamJet. Mane.Rep.No.522,BallisticRes.Labs.(AberdeenFrovingGround,Md.),Ott.12,1950. (ProjectNo’.TB3-01.10of theRes.andDev.Div.,OrdCorps.)

.

.

TABLE I -

NACARME51G26.

16-INCHRAM-JXTOOOIUIINATES.

.

/ L~_ —Station

L

“-(in.)

-5.05-4.0-3.0-2.0-1.001.02.03.04.06.08.010.012.014.016.018.030.046.059.063.068.48193

107169187

Location

Tipofspike[conehalf-angle25°

Lipofinlet(radiusO.O32in.)

Station2

Stationx

Indof centerbody‘ilotairinlets‘ilotmaximumdia-meter

Station3khaustnozzleinlet

Nozzleexit

(i:.)

,00.480.941.411.882.34e.703.103.363.583.944.214.404.524.584.604.584.444.023.082.4301.54.0

3.3

(i:.)

5.055.135.305.455.595.836.036.206.366.486.586.61

1Straighttaper7.757.457.38

8.008.00

(i:.)

5.375.545.695.836.076.286.456.616.726.826.85

!Straighttaper8.13

1

Cylindricalsection

8.13

..—-— -

.

. .

Rii -.

232.5I

!Lreil.ingedge& centerbodysupportstrutsI.oca’tedb thispoBi-tionbut~ incheBt@ BtlW.9JIOf thiS StitiM.1

2254 , ,

E!

Station2 Steticmx

Figure1. - -DIEgl’amaticsk)?tchof &inch ram Jet. v

,.

I.. Nozzle coor.iinatea

oY31gim3centerline llietence frcm Redius.

llp(: y (in.ig.oz)

174 7.85I 175 :‘7.63! 176 7.46

2 L77 7.05

I178 ;6.135179 6.76ml 6.78

1“ 181 6.&3$01

182 7.(36.4

‘#183 7.28

n.+ 184 7.46I

: “

185 7%62

I 186 7.71

~ IU37 ‘ 7.75

6 I

— .Se.m- 10 rivetseqidly epaedn

.-weld

171 173 175 177 179 181 163 185

Distancefl’m lip Of oml, in.

Figure2. - Conmr@ng-diverghg exhaust-nozzlecomdinatee ad nmuting detaih.

+I

187

1 .2157 # ● 2254 , ,

. . -.

- /J—

w

L Primary

Qfuel &fold

AUA”

o 0

A❑

A“

Hozzle .wrmgement atprimwy Ibm.ii’old

.

00

0

0

0

0

0

Hozzle arrangement at

Bec Cmdary manifold

-1—

Nozzle ~r~. direction Nozzle rating

spray (at lm,ly)q in. )

O Conical•1conical.o CmlicdA Flat

I PrimaryISeccmdfaymanifoldmanifold

Radial45°upatrem 1 I 0.667I I.Coo450d-ketremjDcmstre.m I .625 I .625

v

Figure3. - Eurner-cmfiguratbn &lA.ls,

toF

22.

-$&

Combustion-chamber .i&linletMachnumber

i M3mlmo .17 .la

3.13 .14 .15.82

.16/

/ ./</ ~/zA .567 / / /

? ~ / / / ~ y /-507

— ‘d/ /’

_ ~ _ :+ //b ~1 / /

/’ /’.78 1’_ /’

./ /‘/ /’

1/ //’- P /‘ /f.74

.70.55 .&) -:65 .70 .is .00 .85 .20 .95 1.00

Massflowratio,m/~(a) Maohnumber,2.0.”

.94 ..

.90 p “P

{ .14.15, .16/1 / / /

I~“”.436

‘P/

.41 /// II 1

.66/ /

.82

.78.55 .60 ‘.65 .70 .75 .80 .85 .90 .95

Massfiowratio,m/m.

(b) Machnumber,1.8.

“‘6 K30.I.3 .14 .16

,.15 .17 .18 ,.19f .20 *gle(::gytack1 , !.% I // / (n <~ /

/I / / PI II

8

:?/ /

.92 10

! .21 CreasedBymbols indioati

f’ ttburningdatat Flaggedsymbols

/’.88 / pulsingdata )

/ /// t3

.84L.K1 .55 ....60 .“65 .70 .75 .80

Massflowratio ,’m/~ T--”

Indlaatet

.

%“K!

(c) Mach

Figure4.- Diffuserperformanceat

.-

.

.number,1.5.

Maohnumbers1.5,1.8,and2.0for anglesofattackof0°,6°,an?100.

NACARM 151G26w

1

.8

w

23

. .0 i

4

, A

5 Machm.mber

e /s /‘

o% ——- 2.0(calculated+’ .6 of reference6)

.

.4“ o[

.2

0- U

30“

20—-..——-.._

9

10 \\\\

3 Ao

u.05 .lo .15combustion-chamberinletMachnumber,M3

.—

Figure5. - @id-flowstiticpressurefluctuationatdiffuser~itj 0°angleofattack.

dpd-L%

.

.8

.6

.4

.2

0

~=a2: w’g;02g~ omo .075 -125 ,175 .225 .275 .10 .15 .20 .25 .30

Ccmbuetim—chamber inletiMach nuuber,~ ‘

mm 6. - statfmmmm fMOwmtim d MffUew =It and=@O.d SurfaoeofCml forCold-flmdEd burningConaltlmla . Mach number, 1.8; angle of attack,@.

,

“m’

Ill*‘,

.

t,=..”

!2

. ,,,,: 1 I 1\

4 NACA 25

.

Externalcowl

2 lb/sqin.

4 lb/sqin.

Diffuserexit

(a) Cold,combustion-chamberinletMachnumber,O.150.

0.,9lb/sqin.

Externalcowl

O.alb/sqin.

Diffuserexit

(b) Burning,combustion-chamberinletMachnumber,O.153.=S=

Figure7.- Effectofburningondiffuserpressurepulsations.Free-streamMachnumber,1.8:constant-areaexhaustnozzle.

A@=aEi&’”’

26

External.cowl

NACAFME51G26

T0.8lb/sqin..

—

2 lh/6qin.

Diffuserexit—

(a) Combustion-chamberInletMachnumber,0.259.

0.8lb/sqin.

.

.

Externalcowl

0.8lh/sqin.

Diffuserexit

(b) Combustion-chmberinletM8.chnUmber,O.200.-=?3=

Figure8.- Internalandexternaldiffuserpressurepulsatimswith.burni~f’%Supercriticdoperation.Free-strem~~h number?I.e. —

h~ .;.:.

.

.

NACARM Z51G26..

tm@kE#m,.

.

(a) Beginningofcycle.

.

(b)12.5percentofcycle.

(2)25percentofcycle.

(d)37.5percentofcycle.

(e)50percentofcycle.

(f)62.5percentofcycle.

(g)75percentofcycle.

(h)87.5percentofcycle.

(i)Endofcycle.

Fi13ure9.- SequenceofghotographsatinletfoI.cold-flowoperationatMa+number2.0takenbyhighspeedmotionpicturecamera.Angleofattack,6“;frequency,18.7cyclespersecond;diffuserexitamplitudecoefficient,0.36;cmnbustion-chamberinletMachnumber,0.165.

.

.

2.

1.

1.

1.

1.

1.

-.

-.

0 1 2 3 4 0 1 2 s 4 0 1 Qstatic arifioe Lx.8t.b, bOdY U=eterm fmm idet liP

(m) ‘kq mufaoos of ●xwrnml UOU1 and oentcrbcdr,d angleofattack. +

Figvro 10. - variation in m.atia prensure ccefflcientmalmYs difllmr at ,~e-mmem Mach ~m of 1.5. 1..9,and 2.0.

,

I

, ktszz , ,

1 ,, 11’ 1 “

.

, . t ,

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

Staticadfioe looar,lm,bodydiameters from inlet 11P

(b) lbp nnd b.ttrn axtirnal owl muw%oea at angle. of attaok of O“, 6°, and 10°,

Fi&’LG-n10. - Continued. Variation in Statio prennurc oOcffioientB alcq diffuner at free-nta?am Maoh numbern of 1,5, 1.8, and 2.0.

—.

1.6

1.4

1.2!

1.0

.0

.6

.4

.2

12.0

1.

I I I I I I I

/ G--.r -

1.6

1.4

1.2

1.0

..9

.8

I I I I I --h

I -I

.4 1 1 1 I1

1 1 , I , 1 1 , , , I , I2 s 4 0 1 2 s

w4 0 !

staticorifice2 3 4

10U’CIC+I,bcdy di#s?taran’a mot lip

WHFiSWW 10. - CmoludA. Variazicm h stazio pressure c.efflcientw along Ufuser at free-.tre?mMach mnbers or 1.:, 1.8, 81142.0,

z.-

, ● I 1 ● ✌

k!

Total head tube looe.t,im, r/rm

(a) Effeot of angle d attaok;coldflow;omnbuEtiou-&unberInlet!@h nuder, 0.22.

Fi@re 11, - Prufile-sofMad ntnmlmrdlatributionat dmtion x; free-etreamMe-ohnunber,1.8.

.

— facingdmmatream—

AA 4~

kb

b. A

A

wN

.4Angleof attaok,6°

k A P.3-

4 0%

R.2

o A

.1

~“ “ ‘s n ‘ ‘ ‘ ‘4 I.4

.3 /@ 9 A .

t35 0 ; Q.2

0

.1

fmgle& attaak,10°

h ~ AD +

eA

+

4’ A

1.0 .8 .6 .4 v Ov .4 .6 .8 1.0

Total&e&i tubelooatlon,r/r=

(b) EffectM engleof attack;burning;cc+nbmtim+h.mherinlet&h number,0.22.

. \

r .

I

1 2254 . UI

!coW.headtubelocation,r/r=

(c) Emmt of mmstm-dmber WLet W tier, ~; m-;

l?lguren. -Cmolwied. Frdllea d Mad umber Metrilmtinn at stationx;

angle ofattack,0°.

rl’M-etreWJllnlcllnumber,1.8. mw

34...

NACARM E51G26

..34 ,.

.30 .AngleQfattack

(deg)..:

.26

,22

5

w e.

TFFFl60 ,

70

/ L A

60

50

1

.

.03 .04 .05. .06 . .07 .0sFuel.-airratio,f/a

b.”

Figurel~; - Effectofoperationa>angleofattackoncombustion.Machnumber,1.8;co~t~t-wea outletnozzle;cmb~tion:c~ber ‘nlet‘mpera-

. .

ture,135°F; etaticpreaeure,1700to2200poqndspersquarefootabolute.

+%BEmm@-.-:.”*.&.+%.. .., .

.

9

*mNN

NACARM E51G2635

6

1.55 10

1.4

1.3

‘nv.; 1.2+s%‘%:-P

11.1

-P-P~

1.0

.9

.82.4 2.8 3.2 3.6 4.0 4.4 4.8

Combustion-ohambertotal-temperatureratio,T

Figure13. - Jetthrustcoefficientsobtainedwithconstant-areaoutletnozzleat.Maohnumberof1.8andanglesofattackof0°,6°,end10°.

..”.●- d

s~~—

.-

4.

Free-8b-=mH80h~, MO, 2.0

-02 * 4 *

tl-—-U . ❑

c

P

A

ti@

/

c~

5.0 5.0 4.0cmmm%LKAObobAg.ms IntiLl,=

4.5 5.0 5.5 8.0 6.5

CNO-J

IcR.,,,. .,.,.

.

NACARME51G26.

.

37

.4vi lTOzzleerea ratio,AJ~.;

Messflm ratio,nl~ —1.0 (rderanoe1]

~ .,.0.9

— — .6 ---1.0 PIW theoretioalboattail~

.7 dr~ for @A4 d 0.71~ ~ (methoda? oheraoteriatios]

~ ~8 0 .71(oold-flowdata)

j T

.95 lrrhbH7TH

.—_ -- .1 ~ d%~

ii .1,

1.5 1.6 1.7 1.8 1.9 2.0Free-stream Machnumber, ~

Figure15.-Cold-flawengineb~ dregooefffoientafor16-inchremSetwltboonstent-a edconvergingexhmatnozzles.

.24.

SupereritiealjO* 9ubcrLtioal eI o

/ ,0v

~ — A-

‘.161 I\ I [ I 1 1 1 I 1 , # ,-1 ~n t

iJ‘--.$!Mpalm —m-4--ktld.lh IY4111” I IWWH--H

.

Ccazbuetlcu-ohembertotal-temperatureratio,Z

F@we 16.- ZffeotCUburniagonbti &eg ooeffioientforcomerglngoutletnozzleat free-e-emMeohnuinbawof1.5,1.8,cd 2.0end0°angleofattaok.

r

‘lIll1.c

Free-Otream MaOh number, ~, 2.0

vu . .. .. N 1 1 I 1 I Ip-fiwu 1“.1 I I’ll:. I--TsrT tt T

I 1

~ .2\.

!z

%.18 22 .26 3 .34 .38

cmbuBt

outlet nozzle

O cLWI”*arI@6(r~ @ta)

8conver@ngiitvarmConstant -ea

---Theoretical cOnver@.2 divewlng(based cm .onver@.ng-noszle data :

lkJ, 1.8

\

\c

? F ,

.-

7‘~\’ -.

o\

0

.IE .20 .24 .28 .32ion-ahmher inlatMach number,MS

Fiwre 17. - mt titernnltlmmt coefficientsobtaimi with the three outletnozzlesat MRCJImmb=m of,“ of att+ak.

I

$’

*..

143,1.5

h ‘> j\ 1

..

!. ,,

. .

& ‘~

1:16 .20 .24 .!?8

E

1.5, 1.8, and 2.0 at 0° aI@e %

.“ ~

.

.

.

.

RACARM E51G26

Outlet Statiopressurenozzle

(lb/sqp?tabs)

.29 “o Converging 2400-27000 Converging

diverging 2300-27$\ -o constant

statiotemper-atur~t5(%)135

112

135

-:02 . .04 .06 .08 .lo .2-2Fuel-airratio,f/a

Figure18.- Effectof’outletnozzleconfigurationoncombustorperformancefree-streamMachnumberof1.8and0°angleofattack.

.

.—

at

MO, 1.E

\

\\

/ a r/ <

Outlet ncmzle

‘ 1

. . t .,, t Wzz

. . , . . .

8

Free-stream Uaoh number, Mo, 2,0

..9- \

~

g

: -4 \ bg+! Yg

11-0 Converging(basedm

oold-bo~ drag)❑ &v&r%&ver@rL2

(referenoe1)H

Ho, 1.8

k3

\ ,

.M ,m .24 .22 .52.cm-chmberInlet Umh number,M3

FIw.s 20.- VUlatlOnofpm3puIBlm thrUBt Qoeffioient with ombu.stlon-ohamber Inlet t480h IWMbeP fornumbern of 1.5, 1.8, and 2.0 and 0° angle of attack.

b, 1.5

~ \

b

\

I:6 .20 .24 .28

the three catlet nozzleo at Mnch

., .,i,