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简介：Heattransferinthethrustchamberisofgreatimportanceinthedesignofliquidpropellantrocketengines.Regenerativecoolingisandadvancedmethodwhichcanensurenotonlytheproperrunningbutalsohigherperformanceofarocketengine.Thetheoreticalmodeliscomplicated,itrelatestofluidbynamics,heattransfer,combustion.etc…,Inthispaper,aregenerativecoolingmodelispresented.Effectssuchasradiation,heattransfertoenvironment,variablethermalpropertiesandcokingareincludedinthemodel.Thismodelcanbeappliedtoallkindsofliquidpropellantrocketenginesaswellassimilarconstructions.Themodularizedcomputercodeiscompletedinthework.

简介：Thisworkpresentsanumericalsimulationoftheflowfieldinaliquidpropellantrocketenginechamberandexitnozzleusingtechniquestoallowtheresultstobetakenasstartingpointsfordesigningthosepropulsivesystems.ThiswasdoneusingaFiniteVolumemethodsimulatingthedifferentflowregineswhichusuallytakeplaceinthosesystems.Astheflowfieldhasregionsrangingfromthelowsubsonictothesupersonicregimes,thenumericalcodeused,initiallydevelopedforcompressibleflowsonly,wasmodifiedtoworkproficientlyinthewholevelocityrange.ItiswellknownthatcodeshavebeendevelopedinCFD,foreithercompressibleofincompressibleflows,thejointtreatmentofbothtogetherbeingcomplexeventoday,giventhesmallnumberofreferencesavailableinthisarea.Hereanexistingcodeforcompressibleflowwasusedandprimitivevariables,thepressure,theCartesiancomponentsofthevelocityandthetemperatureinsteadoftheconservedvariableswereintroducedintheEulerandNavier-Stokesequations.ThiswasdonetopermitthetreatmentatanyMachnumber.Unstructuredmesheswithadaptiverefinementswereemployedhere.Theconvectivetermsweretreatedwithupwindfirstandsecondordermethods.ThenumericalstabilitywaskeptwithartificialdissipationandinthespatialcoverageoneusedafivestageRunge-KuttaschemefortheFluidMechanicsandtheVODE(ValueofOrdinaryDifferentialEquations)schemealongwiththeChemkinIIinthechemicalreactingsolution.Duringthedevelopmentofthiscodesimulatingtheflowinarocketengine,comparisontestsweremadewithseveraldifferenttypesofinternalandexternalflows,atdifferentvelocities,seekingtoestablishtheconfidencelevelofthetechniquesbeingused.ThesecomparisonsweredonewithexistingtheoreticalresultsandwithothercodesalreadyvalidatedandwellacceptedbytheCFDcommunity.

简介：AgingofasolidcompositepropellantcontainingHTPB/AP/ALwasperformedinordertovalidatetheconformanceoftheacceleratedagingdatatotheArrheniuslaw.Themainobjectiveoftheworkwastoexaminetheinfluenceoftheaziridinebondingagentsfamilyonthepropellantaging.Agingofthepreparedpropellantsampleswasconductedasfollows:1.Foursamples,onefreeofbondingagents,andthreecontainingaziridinebasedbondingagentsMAPO,HX-752,MAT4wereagedat65°C.2.AnotherfoursamplesbasedonHX-752,MAT4withdifferentcuringagentswereagedat65°C.Themeasuredmechanicalpropertiesofthefreebondingagentpropellantsampleswereveryfarfromthespecificationsandthisillustratestheimportanceofthebondingagentsinboththepreparationandtheagingphases.Thepreparedbondingagent"MAT4"gaveremarkableimprovementsofthemechanicalpropertiescomparingwithHX-752andMAPO.Theaziridinebondingagentsfamilyinhibitedtherateofdecompositionofthepropellantduringtheagingperiodsandsupportedthepropellantmatrixagainstdecompositionattheelevatetemperatures.UsingofHMDIascuringagentgaveslightbettermechanicalpropertiestotheIPDI.

简介：Atime-resolvednumericalcomputationalapproach,involvingthecombustionofdouble-basepropellantisperformedonthermalprotectionmaterialforSRMnozzle.AnimplicitNavier-StokesSolverisselectedtosimulatetwo-dimensionalaxial-symmetricunsteadyturbulentflowofcompressiblefluid.ThegoverningequationsarediscreditedbyusingthefiniteVolumemethod.S-Aturbulencemodelisemployed.CFDschemeisimplementedtoinvestigatethetemperaturedistributioncausesatnozzlethroatinsertscompositematerial.DifferentparametershavebeenselectedfortheanalysistovalidatethetemperaturevariationinthethroatinsertsandbakingmaterialofSRMnozzle.TheadvancedSRMnozzlecompositematerialisalsocharacterizedforthehighthermostabilityandhighthermomechanicalcapabilitiestomakeitmorereliable,simplerandlighter.

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简介：Inthispaper,astudyofthehigh-speedgasjetofarocketnozzleunderwaterwascarriedoutusingcommerciallyavailableCFDsoftwareFLUENTwithit'suser-defined-function.Thevolumeoffluidtechniquebasedonfinitevolumemethodwasadoptedtosolvethetime-dependentmultiphaseflowincludingacompressiblephase,andthePISOalgorithmwasincluded.Thecomputedresultsshowthatthisproblemwascalculatedsuccessfully.Thegasbubblebehindthenozzle,andthewavestructureexistinginhighlycompressedgasinwaterwerecapturedaccurately.

简介：《瓶装火箭》是一部幽默的电影,这种幽默被裹上了一套笨拙的外衣,存在于影片的每一个角落。在塞林格著名的《麦田守望者》里,有这么一段话:我一直会想像很多小孩在麦田地里玩游戏。有几千个人,无一例外都是小孩,除我之外。我会站在这混账的悬崖边上,我的职责就是守望,我要做的就是抓住每一个跑向悬崖的孩子,因为一旦他们开始奔跑,就不知道会

简介：这开发的目的是检测在后膛之间的并行水平的站台和火箭火炮的资料试管轴。在口套的定位瞄准机制和在后膛的定位调整机制在系统被设计。除那些以外，系统也一起与1'和一面瞄准镜子的精确性使用一个准直望远镜决定资料试管的轴。有2'的精确性的电子水平被采用测量并且显示包括的角度和使倾向的方向的参数的值。这个系统的全部精确性是

简介：为了在impellers压制成穴并且做涡轮泵，更长生活，inducer与主要impeller被分开，两impellers独立地被驾驶。在impellers附近的泵和流动条件的表演试验性地被调查，下列结果被获得。(1)主要impeller贡献在inducer和主要impeller之间的流动相互作用。(2)两impellers的旋转速度能独立地被控制以便同时总体上压制成穴不仅impeller，而且在inducer。

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