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简介：Thecastablesforladlenozzleweredevelopedusingbrowncorundumasthemainrawmaterialandtherightamountsofcomplexadditives.Theinfluenceofseveraladditivesonthepropertiessuchasstrengthandpermanentlinearchangeofthesampleswasstudied.Theresultsshowedthatapplyingcomplexadditivesimprovedthestrengthandthevolumestabilityofthecastablesgreatly.Thecampaignofthecastablesforladlenozzlehasincreasedfromabout40heatsto70heats.

简介：Cavitationisoneofthetroublesomeproblemsinrocketturbopumps,andsincemostofhigh-efficiencyrocketpropellantsarecryogenicfluids,socalled'thermodynamiceffect'becomesmoreevidentthaninwater.Inthepresentstudy.numericalandexperimentalstudyofliquidnitrogencavitationin2DLavalnozzlewascarriedout,sothattheinfluenceofthermodynamiceffectwasexamined.Itwasrevealedthattemperatureandcavitationhavestronginter-relationshipwitheachotherinthermo-sensitivecryogenicfluids.

简介：Thermalfatigue(TF)isoneofthemostimportantfactorsthatinfluenceturbine'slife.Thispaperestablishesa3Dsolid-fluidcouplingmodelforasteadytemperatureanalysisofahigh-pressureturbinenozzleatdifferentturbineinletgastotaltemperatures(TIGTTs).Thetemperatureanalysissuppliesthetemperatureloadforsubsequent3Dfiniteelementanalysistoobtainthestrainvalues.Followingthis,thepredictionoftheTFlifeismadeonthebasisofequivalentstrainrange.TheresultsshowthatthestrainincreaseswithTIGTT,andthepredictedTFlifedecreasescorrespondingly.ThislifepredictionwasconfirmedbyoneTFtest.

简介：高效率的优点，低SFC(特定的燃料消费)，超离频绕过比率扇涡轮引擎吸引越来越多的注意在现代广告引擎。中间的汽轮机管(ITD)它高连接有低压力的压力汽轮机(HPT)汽轮机(并行口)，由指导流动没有太多损失，从HPT来到并行口在汽轮机的全面表演上有批评影响。因此，掌握设计好攻击的、甚至超级好攻击的ITD的技术变得越来越迫切。更多担心被专注于管。然而，改进汽轮机以便推进，并行口嘴被排列成ITD弄短低压力轴。与如此的设计概念，那块并行口嘴流动地被在上游的管结构容易影响，是明显的，但是相反收到少得多兴趣。在这份报纸，数字方法被用来调查一些ITD的效果与在上游打漩并行口上的片嘴。有一样的九个模型打漩并且嘴片当ITD的长度是唯一的时要换掉的参数，将被讨论。最后，为设计者的几个结论和忠告被总结。在改变管，入口和插头的轴的长度以后，嘴的流动地相应地不同。在另一方面，表面介绍的嘴片(吸和压力)上的砍的压力在各种各样的入口流动下面的单个特征。除了那，像计时的效果在这份报纸被描述，它将贡献大部分到压力损失并且应该被付足够的注意。

简介：SeveralkindsofslidenozzleplatesuchasAl2O3-C-ZrO2,MgO,Al2O3,Spinel-CandAl2O3-CSNplateforhighoxygensteelusedinBaoSteelhavebeenanalysed,theappearanceandsizeoftheSNplateafterusinghavebeenmeasured.TheAl2O3-CSNplatehaslongerservicelifeincastinghighoxygensteel,andthewearmechanismofdifferentSNplatesisdiscussed.

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

简介：在连续热剧降的电镀的过程控制锌的电影厚度，它从早天被知道通过一把空气刀的煤气的擦去是最有效的。擦在电镀使用过程的气体引起为涂层的某个高速度从长带边打起浪花的一个问题。在现在的学习，喷气结构和在板表面侵犯压力的分发上的Coanda嘴的偏转角度的效果因此数字地并且试验性地被调查。在数字分析，管理方程由三维的时间组成了依赖完整的海军司烧方程，标准k-吗？等等解决狂暴的应力的骚乱模型被雇用。在实验，16隧道压力扫描阀门和3轴汽车穿越单位被用来在长带表面测量侵犯的压力。作为结果，它被发现那为空气刀的一样的嘴裂缝的偏转角度越小，侵犯的压力是越多larger。减少分离水泡的尺寸并且提高切的能力，与Coanda嘴使用一把空气刀是明智的。

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

简介：Theeffectofnozzlegeometryonsoniclineandcharacteristicsofsupersonicairjetwasstudied.Computationalfluiddynamicswasappliedinthisstudy.Theaxisymmetricnozzlegeometriesinvestigatedweretwodifferentcontourconvergingnozzles,twodifferentconicallyconvergingsharp-edgednozzlesandasharp-edgedorifice.Theresultsshowthatthesupersonicjetstructure,soniclineandstreamlinesinsupersonicjetarestronglyinfluencedbythenozzlegeometry,andthetotalpressurelossincreaseswiththeincreaseofMachdiskdiameter.Thepresentnumericalsimulationisaneffectivetooltoevaluatecompressibleflowsinsupersonicairjet.

简介：Whencondensationoccursinsupersonicflowfields,theflowisaffectedbythelatentheatreleased.Inthepresentstudy,Navier-Stokesequationsweresolvednumericallyusinga3rd-orderMUSCLtypeTVDinite-differenceschemewithasecond-orderfractional-stepfortimeintegration,Baldwin-Lomaxmodel,thatisthealgebraicmodel,calledthezeroequationmodelwasusedinthecomputations.Theeffectsofinitialconditions(initialdegreeofsupersaturationandtotaltemperatureinthereservoir)oncondensingflowofmoistairinasupersoniccircularhalfnozzlewereinvestigated.Inthiscase,theeffectofcondensationontheboundarylayerwasalsodiscussedindetail.Asaresultthesimulatedflowfieldswerecomparedwithexperimentaldataingoodagreement,andthevelocityandtemperatureprofileswerelargelychangedbycondensation.

简介：Thesupersonicnozzleisthemostimportantdeviceofanejector-diffusersystem.Thebestoperationconditionandoptimalstructureofsupersonicnozzlearehardlyknownduetothecomplicatedturbulentmixing,compressibilityeffectsandevenflowunsteadinesswhicharegeneratedaroundthenozzleextent.Inthepresentstudy,theprimarystreamnozzlewasredesignedusingconvergentnozzletoactivatetheshearactionsbetweentheprimaryandsecondarystreams,bymeansoflongitudinalvorticesgeneratedbetweentheChevronlobes.Exactlysamegeometricalmodelofejector-diffusersystemwascreatedtovalidatetheresultsofexperimentaldata.TheoperationcharacteristicsoftheejectorsystemwerecomparedbetweenChevronnozzleandconventionalconvergentnozzlefortheprimarystream.ACFDmethodhasbeenappliedtosimulatethesupersonicflowsandshockwavesinsidetheejector.ItisobservedthattheflowstructureandshocksystemwerechangedandprimarynumericalanalysisresultsshowthattheChevronnozzleachieveapositiveeffectonthesupersonicejector-diffusersystemperformance.TheejectorwithChevronnozzlecanentrainmoresecondarystreamwithlessprimarystreammassflowrate.

简介：与打漩的以前的研究比较流动，在螺线嘴产生的螺线流动有一些不同流动特征。产生它的速度不需要强迫的正切的动量并且从象长潜在的核心和低正切的速度那样的打漩的流动有一些不同优点。在这研究，在螺线嘴的流动特征上的嘴几何学的效果被实验和计算调查。作为结果，实验获得的流动特征与计算结果，份量上和品质上有一个令人满意的协议。

简介：Aphysicalmodelwithmercuryasanalogwasdevelopedtoinvestigatetheinfluencesofelectromagneticstirring(EMS)onflowfieldinslabcontinuouscastingwhenthesubmergedentrynozzle(SEN)wascloggedwithdifferentcloggingrates(0,10%,25%,and50%).TheflowfieldinmoldunderdifferentEMScurrents(0,40A,and60A)wasmeasuredbyanultrasonicDopplervelocimeter.Theresultsprovedthattheflowfieldinthemoldwasatypicaldoublerollstructureundernon-cloggingSEN.AstheSENcloggingrateincreased,theflowfieldstructurewastransformedfromadoublerolltoasymmetryflow.Whenthecloggingratereached50%,theupcirculationdisappearedonthecloggedside.Thezoneunderthemeniscusnearthenarrowfacewasanon-flowingarea.EMScouldcorrectbiasflowcausedbySENcloggingandimprovethesymmetryoftheflowfieldduringSENclogging.

简介：Inordertoshortenaero-engineaxiallength,substitutingthetraditionallongchordthickstrutdesignaccompaniedwiththetraditionallowpressure(LP)stagenozzle,LPturbineisintegratedwithintermediateturbineduct(ITD).Inthecurrentpaper,fivevanesofthefirststageLPturbinenozzleisreplacedwithloadedstrutsforsupportingtheengineshaft,andprovidingoilpipescircumferentiallywhichfulfilledtheareo-enginestructurerequirement.However,theirbulkygeometricsizerepresentsamoreeffectiveobstacletoflowfromhighpressure(HP)turbinerotor.ThesefivestrutsgiveobviousinfluencefornotonlytheLPturbinenozzlebutalsotheflowfieldwithintheITD,andhencecausehigherloss.NumericalinvestigationhasbeenundertakentoobservetheinfluenceoftheNozzle-StrutintegrateddesignconceptontheflowfieldwithintheITDandthenearbynozzleblades.Accordingtothecomputationalresults,threemainconclusionsarefinallyobtained.Firstly,anoticeablelowspeedareaisformednearthestrut'sleadingedge,whichisnodoubtcausedbythepotentialfloweffects.Secondly,moresevereradialmigrationofboundarylayerflowadjacenttothestrut'spressuresidehavebeenfoundnearthenozzle'strailingedge.Suchboundarylayermigrationisobvious,especiallyclosetotheshrouddomain.Meanwhile,radialpressuregradientaggravatesthisphenomenon.Thirdly,velocitydistributionalongthestrut'spressuresideonnozzle'ssuctionsurfacediffers,whichmeansloadingvariationofthenozzle.Anditwillnodoubtcausenonuniformflowfieldfacedbythedownstreamrotorblade.

简介：Dependentonautomaticallygeneratedunstructuredgrids,acomprehensivecomputationalfluiddynamics(CFD)numericalsimulationisperformedtoanalyzetheinfluenceofnozzlegeometryontheinternalflowcharacteristicsofamulti-holedieselinjectorwiththemulti-phaseflowmodelbasedonEulerianmulti-fluidmethod.Thedieselcomponentsinnozzleareconsideredastwocontinuousphases,dieselliquidanddieselvaporrespectively.Consideringthatbothofthemarefullycoupledandinterpenetrated,sepa...

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