Development of a liquid-fed water resistojet

DEVELOPMENTOFALIQUID-FEDWATERRESISTOJETW.EarlMorrenandJamesR.StoneNatlonalAeronautlcsandSpaceAdministrationLewisResearchCenterCleveland,Ohlo44135Abstract determinedthata slmple,integratedvaporlzer/superheatercouldbebuiltthatwouldserveasaA conceptforaforced-flowonce-throughwater one-plecethruster.Laboratorymodelverslonsofvaporizerforappllcat|ontoreslstoJetthrusters thlsthrusterweredeslgned,constructed,andwasevaluatedasanelementofa laboratorymodel testedtoverifythedeslgnconceptandInvestl-thrusterandtestedtoinvestigateItsoperating gateItsoperatlonaIcharacterlstlcs.Forapp11-characterlstlcs.Thevaporizerdesignconcept catlontoSpaceStation,wherebothgaseousandemploysflowswirlingtoattachtheliquidflowto liquidpropellantsmightbeused,aseparatevapo-c_ theboilerchamberwall,providingforseparation rlzerbasedon thlstechnologymightbeof inter-of thetwofluidphases.Thlsvaporizerwasmodl- est. Thlspaperwilldiscussthebasicboilingfledwitha nozzleanda centrally-locatedheater theoryusedtoarriveatthlsdesign,presentatofacilitatevaporization,superheating,and detaileddescriptionof thedesign,presenttheexpansionof thepropellant,allowingIttofunc- resultsofperformancemapping,anddiscussthetlonasaresistoJet.Performancewasmeasured characteristicsofa liquid-fedwaterreslstoJetatthrustlevelsrangingfrom170to360mNand propulslonsystem.atpowerlevelsranglngfrom443Wto904W. Max-imummeasuredspecificimpulsewas192sec. TheoryIntroduction ThebollerrequiredforapplicationtowaterreslstoJetsIstheforced-flow,once-throughtype,Thlspaperdescribestheprogressofapro- Incontrasttotheslmplerandmorecommonpot-gramtodevelopa reslstoJetsystemcapableof typeboilers.Tointegratewitha contlnuous-flowoperationonwaterpropellant.Multlpropellant propulsionsystem,thesubcooiedilquldIscon-reslstoJets,forwhichwaterisa candidatepro- vertedintosuperheatedvaporina singlepasspellant,havebeenbasellnedasthelow-thrust throughtheboiler. Extensive11quldboilingpropulsionsystemoptionfortheSpaceStatlon.I researchwasconductedInthe1960'sandearlyHaterresistoJetshavealsobeenbasellnedfor 1970'sassummarizedbyStone,eta1.5 Fortheorbltmalntenancedutyon theman-tendedIndus- reader'sconvenience,somebasicconsiderationstrlalSpaceFac111tyscheduledforlaunchinthe importanttothedesignof forced-flowonce-early1990's.2 throughboilersarerepeatedInthlssectionaspresentedinRef.S. However,thisInformatlonTheuseofwaterasareslstoJetpropellant hasbeencondensedsignlflcantlytoIncludeonlyformannedorman-tendedplatformshasanumberof thatwhichIsgermanetowaterreslstoJetdesign.attractlvefeatures.ScavengedwastewaterwhlchmightotherwisehavetobereturnedtoEarthcould Backqroundbeusedtoprovideimpulsefordragmake-upororbitcontrol.Spacesystemswhichoperateon Duringthebol1|ngofa 11quldflowlngwatereconomiescouldstorellquldwatereasilyin throughachannel,severalheattransferregimessma11,low-pressuretanks,electrolyzethiswater areencountered.A typlcalcaseIsillustratedforuseInhydrogen/oxygenrocketstoperform InFlg.I. The11quldtobevaporizedentersthehlgh-thrustpropulslontasks,andusewaterfrom channelandIsheatedInthe11quldphasetothethesamestoragetankstofeedwaterreslstoJets pointwherebubblenucleatlonfirstoccurs.forlow-thrustpropulslon.Furthermore,the NucleatebolllngcontlnuesuntllenoughvaporIsbenignchemlstryofwaterandsteammakesItwell- generatedthattheresultlngincreaseInvelocltysuitedtomannedsystems,wheretoxlcltyandcon- Issufflclenttosuppressnucleatlon.Beyondthlstamlnatlonareofgreatimportance, point,heatIsaddedtoa thln11quldf11mandvaporlzatlonoccursat the11quld-vaporInterface.Haterwasoneof thecandldatepropellants Throughouttheseboilingregimes,IlquldIsbeingforablowastereslstoJetsysteminvestigatedas entralnedInthevaporcore. Despiteanyredepo-partof theMannedOrbltalResearchLaboratory sltlonof 11quldfromthecoretothefllm,at(MORL)programconductedduringtheearlyIg70's. somepolntthereIsnolongersufflclent11quldtoPrellmlnaryevaluatlonofbaslccomponentsInclud- wetthewa11. The11quldf11mbreaksdownwithaIngthrusters,steamqenerator,compressors,and largereductionInheattransfercoefflclent,pumpswasundertaken.3,4 TheMORLprogramandthe oftenmorethananorderofmagnitude.Thlstran-associatedblowastereslstoJettechnologyworkwas sltlonhasvarlouslybeentermed"bo111ngcrisis,"terminatedIntheearly1970's. "departurefromnucleatebo111ng,"and"burnout,"aswellasothernames. ThlsfllmbreakdownisRecently,a programwasinitiatedtodevelop generallyfollowedbyatransltlonalregimewhereintechnologyforawatervaporizercapableofpro- aconslderableamountof11quldremainson thevldlngsteamtothemultlpropellantreslstoJet wa11. Eventually,onlya few11qulddropletscurrentlybasellnedIntheSpaceStatlonpropul- remainonthewa11,andmostof theheataddedslonsystem. Thewatervaporizerdeslgnedunder throughthewallgoesIntoheatingthevapor. IttheMORLprogramwasInvestlgated,butrejectedIn thenbecomesdlfflculttovaporizetheremainingfavorofa newdesignwhichIsdlscussedInthis droplets.paper. Durlngthlstechnologyprogram,Itwas