The NASA Langley Scramjet Test Complex R. Wayne Gu

TheNASALangleyScramjetTestComplexR.WayneGuy,*R.ClaytonRogers,*RichardL.Puster,†KennethE.Rock,‡andGlennS.Diskin‡NASALangleyResearchCenterHampton,Virginia23681-0001AbstractTheNASALangleyScramjetTestComplexconsistsoffivepropulsionfacilitieswhichcoverawidespectrumofsupersoniccombustionramjet(scramjet)testcapabilities.ThesefacilitiespermitobservationoftheeffectsonscramjetperformanceofspeedanddynamicpressurefromMach3.5tonear-orbitalspeeds,enginesizefromMach4to7,andtestgascompositionfromMach4to7.IntheMach3.5to8speedrange,thecomplexincludesadirect-connectcombustortestfacility,twosmall-scalecompleteenginetestfacilities,andalarge-scalecompleteenginetestfacility.Inthehypervelocityspeedrange,ashock-expansiontubeisusedforcombustortestsfromMach12toMach17+.Thisfacilityhasrecentlybeenoperatedinatunnelmode,toexplorethepossibilityofsemi-free-jettestingofcompleteenginemodulesathypervelocityconditions.ThispaperpresentsadescriptionofthecurrentconfigurationsandcapabilitiesofthefacilitiesoftheNASALangleyScramjetTestComplex,reviewsthemostrecentscramjettestsinthefacilities,anddiscussescomparativeenginetestsdesignedtogaininformationaboutgroundfacilityeffectsonscramjetperformance.NomenclatureArargonCH4methaneCO2carbondioxideFPIfuelplumeimaginghenthalpyH2hydrogen___________________*AerospaceResearchEngineer,HypersonicAirbreathingPropulsionBranch,SeniorMemberAIAA.†AerospaceResearchEngineer,8’HTTOperationsTeam.‡AerospaceResearchEngineer,HypersonicAirbreathingPropulsionBranch,MemberAIAA.Theuseoftrademarksornamesofmanufacturersinthispaperisforaccuratereportinganddoesnotconstituteanofficialendorsement,eitherexpressedorimplied,ofsuchproductsormanufacturersbytheNationalAeronauticsandSpaceAdministration.Copyright1995bytheAmericanInstituteofAeronauticsandAstronautics,Inc.NocopyrightisassertedintheUnitedStatesunderTitle17,U.S.Code.TheU.S.Governmenthasaroyalty-freelicensetoexerciseallrightsunderthecopyrightclaimedhereinforgovernmentpurposes.Allotherrightsarereservedbythecopyrightowner.H2OwatervaporGcombustorgapsizeLOSline-of-sightmfacilitytotalmassflowrateMMachnumberN2nitrogenNOnitricoxideNO2nitrogendioxideOatomicoxygenO2oxygenOHhydroxylradicalppressureqdynamicpressureReReynoldsnumberSiH4silaneTtemperaturevvelocityXaxialdistanceαwwedgeanglesimulatingaircraftangle-of-attackϕfuelequivalenceratioηefficiencyΔFfuel-onminusfuel-offscramjetaxialforceSubscriptsccombustioninjfuelinjectionconditionmmixingtg*testgast,plenstagnationconditioninthefacilityplenumchambert,1stagnationconditiondownstreamofaircraftbowshockt,∞stagnationconditionupstreamofaircraftbowshock1staticconditiondownstreamofaircraftbowshock2staticconditionatscramjetcombustorentrance∞staticconditionupstreamofaircraftbowshock*TheflowexitingthenozzlesofthefacilitiesoftheNASALangleyScramjetTestComplexcanberepresentativeofflowconditionsupstreamofaflightvehicle,downstreamofavehiclebowshock,orattheentrancetoascramjetcombustor.Therefore,inthispaper,theflowexitingthenozzlesandenteringthetestmodelwillbereferredtoas“testgas”withthesubscript“tg.”IntroductionScramjetresearchintheUnitedStateshistoricallyhasbeencyclicinnaturewithperiodsofveryintenseactivitysurroundedbycomparativelulls(ref.1).Thefirstperiodofscramjetactivitybeganintheearly1960’sandendedwiththeconclusionoftheHypersonicResearchEngine(HRE)project(ref.2)about1975.Afteranationallullinscramjetresearchactivityfromabout1975to1985,researcheffortsagainbecameintensewiththestartoftheNationalAero-SpacePlane(NASP)Program.SignificantaccomplishmentsweremadeduringtheNASPProgram,butresearchactivitydeclineddramaticallywiththeterminationoftheprogramin1994.Coincidentwiththeseactivescramjetresearchperiodswastheemergenceofnewandreactivatedhypersonicpropulsiontestfacilitiesforairbreathingengines(ref.3).Thesefacilitiesaredistinguishedfromhypersonicaerodynamicfacilitiesbytherequirementthatthepropulsiontestfacilitiesduplicatethestagnationenthalpyofflight,theMachnumberenteringtheengineorenginecomponentundertest,andtheoxygenmolefractionofatmosphericair.ThepropulsioncommunityrealizedatthestartoftheNASPProgramthatthecountrywasseverelylackinginairbreathingpropulsiontestcapability.MostofthefacilitiesusedduringtheHREerawereeitheronstandby,mothballed,ordisassembled.TheonlygovernmentfacilitiesactivelyoperatingasscramjettestfacilitieswereNASALangley’sDirect-ConnectSupersonicCombustionTestFacility(refs.4-5),Combustion-HeatedScramjetTestFacility(refs.6-8),andArc-HeatedScramjetTestFacility(refs.9-11).Inaddition,priortothestartoftheNASPProgram,Langley’s8-FootHighTemperatureTunnel(8-FootHTT)wasundergoingrenovationandupgradewiththeadditionofanoxygenreplenishmentsystemandtwonewnozzles(Mach4and5)tosupplementtheexistingMach7nozzle.Thisextensionofcapabilitiesenabledthe8-FootHTTtobeusedasascramjettestfacility(refs.12-14).AstheNASPProgramgainedmomentumafter1985,newandreactivatedpropulsionfacilitieswereapartofthetechnologydevelopmentplan.NASP-fundedEngineTestFacilitieswereconstructedatAerojet(ref.15)andmodifiedatMarquardt(ref.16)withthegoaloftestingcompletesubscalescramjetenginemodulesatM