简介：Steadywatersurfaceprofileofgraduallyvariedflowcanbecalculatedusingei-therasteadyflowapproachoranunsteadyflowapproach.Thesteadyflowapproachrequiresit-erativeprocedureswhichmayhaveconvergenceproblemsunlessthestepsize1xislessthanamaximumvalue△x.Theunsteadyflowapproachbasedontheexplicitcharacteristicmethodhasastabilityproblemunless△xislessthan△x.Aseriesofnumericalexperimentswerecarriedoutandtheresultsoftwoapproachesarecompared.

简介：试验性的调查为斜流动扇子的定子的内部流动被进行。中心表面和定子片的吸表面附近的角落分离上被集中。以设计流动率，在定子插头减少的轴的速度和全部的压力的价值接近吸表面在在由角落墙的影响的中心表面附近。以设计流动率的8090%的低流动率，表面能被发现的在吸表面和中心之间的角落分离，它广泛地变得在设计流动率的80%传播了。

简介：ＴＨＥＭＯＮＳＯＯＮＩＮＦＬＵＥＮＣＥＤＢＹＢＡＳＩＣＦＬＯＷＡＮＤＳＨＥＡＲＦＬＯＷＩＮＳＯＵＴＨＡＳＩＡ￥ＷａｎｇＹｏｎｇｚｈｏｎｇａｎｄＸｉａＹｏｕｌｏｎｇ王永中，夏友龙（ＢｅｉｊｉｎｇＭｅｔｅｏｒｏｌｏｇｉｃａｌＩｎｓｔｉｔｕｔｅ，Ｂｅｉｊｉ...

简介：ThesupersonicductflowwithfixedbackpressuretostagnationpressureratioPb/P0underheatingisinvestigatedanalytically.A“FlowPatternDiagram”Whichconsistsofsixpatternzonesisdeveloped.BythisdiagramtheactualflowstateinsupersonicductflowsystemcanbedeterminedconvenientlywhenPb/Poandheatingintensityareknows.Itisimpossibleforflowwithheavyheatingtobecomesupersonic,eventhoughthepressureratioismuchsmallerthanthecriticalpressureratio,Basedontheanalogybetweenviscouseffectandheatingeffectathermaldragfactorhaseendefined.whichcanpredicttheflowpropertyvariationduetoheatingandtherelaiveimportanceofviscouseffectandheatingeffect.

简介：Allexistingprotonexchangemembrane(PEM)fuelcellgasflowfieldshavebeendesignedonthebasisofsingle-phasegasflowdistribution.Thepresenceofliquidwaterintheflowcausesnon-uniformgasdistribution,leadingtopoorcellperformance.Thispaperdemonstratesthatagasflowrestrictor/distributor,asiscommonlyusedintwo-phaseflowtostabilizemultiphasetransportlinesandmultiphasereactors,canimprovethegasflowdistributionbysignificantlyreducinggasmal-distributioncausedbyeithernon-uniformwaterformationinparallelflowchannelsorflowinstabilityassociatedwithnegative-slopepressuredropcharacteristicoftwo-phasehorizontalflowsystems.

简介：Experimentswereconductedtoinvestigatetheeffectofimpellergeometryandtongueshapeontheflowfieldofcrossflowfans.Threeimpellers(Ⅰ，Ⅱ，Ⅲ）havingsameouterdiameter,butdifferentradiusratioandbladeangleswereemployedfortheinvestigation.Eachimpellerwastestedwithtwotongueshapes.Flowsurveywascarriedoutforeachimpellerandtongueshapeattwoflowcoefficients.andforeachflowcoefficientatdifferentcircumferentialpositions.Theflowistwo-dimensionalalongthebladespanexceptneartheshrouds.Thetotalpressuredevelopedbytheimpellersineachcaseisfoundtobemaximumatacircumferentialpositionofaround270°.Thetotalandstaticpressuresattheinletofimpellersaremoreorlesssameregardlessofimpellerandtonguegeometry,buttheyvaryconsiderablyatexitoftheimpellers.ImpellerⅢwithtongueT2developshighertotalpressureandefficiencywhereasimpellerⅡwithtongueT2developsminimumtotalpressure.HigherdiffusionandsmallervortexsizearethereasonsforbetterperformanceofimpellerⅢwithtongueT2。

简介：BasedonthePreissmannimplicitschemefortheone-dimensionalSaint-Venantequation,themathematicalmodelforone-dimensionalrivernetworksandcanalnetworkswasdevelopedandthekeyissuesonthemodelwereexpatiatedparticularlyinthisarticle.Thismodelappliesthemethodofthree-stepssolutionforchannel-junction-channeltosimulatetherivernetworks,andtheGausseliminationmethodwasusedtocalculatethesparsematrix.Thismodelwasappliedtosimulatethetree-typeirrigationcanalnetworks,complexloopedchannelnetworksandtheLowerColumbiaSloughnetworks.TheresultsofwaterlevelanddischargeagreewiththedatafromtheAdlulandfielddata.Themodelisprovedtoberobustforsimulatingunsteadyflowsinrivernetworkswithvariousdegreesofcomplexstructure.Thecalculatedresultsshowthatthismodelisusefulforengineeringapplicationsincomplicatedrivernetworks.Futureresearchwasrecommendedtofocusonsettingupecologicalnumericalmodelofwaterqualityinrivernetworksandcanalnetworks.

简介：Theformulaswhicharesuitabletobirefringentmediumwithsymmetricplanearederivedbymeansofphaseretardintegration.Wehaveadoptedthisconcepttotheaxisymmetricproblemsanddeducedsomeusefulformulasforthesecases.Asapracticalapplication,thestrainrateanalysisofflowinadivergingoraconvergingvesselisillustratedattheendofthispaper.

简介：ＴＨＥＬＩＮＥＡＲＳＥＰＡＲＡＴＥＤＦＬＯＷＭＯＤＥＬＦＯＲＴＷＯ－ＰＨＡＳＩＦＬＯＷＩＮＳＴＡＢＩＬＩＴＹＩＮＢＯＩＬＩＮＧＣＨＡＮＮＥＬＳ￥ＺｈｏｕＹｕｎ－ｌｏｎｇ；ＳｈｅｎＺｅｎｇ－ｍｉｎｇ；ＳｈｉＨｕｉ－ｘｉａｎ（ＮｏｒｔｈｅａｓｔＣｈｉｎａ...

简介：Basedonestablishednumericalmethodsandhydrodynamicperformancetestingfacilities,CFDtechniqueareappliedtoimprovethedesignoftheimplantableaxialflowbloodpumpandtheflowanalysis.(1)Applyingbrushlessmachinemagnetsteel,reducingitsthicknesswhileincreasingthelength,theflowchannel'scross-sectionisincreased,withnospaceconnectionbetweenthelargeandthesmallrotators,andwithaconetransitionsegmentfromthebearingtotheprincipalaxis,theflowismadesmoother.Therotatingspeedisloweredby1000rpm-1200rpmunderthesameflowrateandpressurehead,andthusthehemolysiscanbeavoided.(2)Differentoutletstatorguidingvanesareselectedforthesamebloodpumpforanalysesofhydrodynamicperformancesandflowfields.Anexcellentdesignnotonlycanregulatetherotatingflowfieldintoanaxialone,reducethecirculationlossandimprovethepumpefficiency,butalsocanavoidbackflow,vortexandsecondaryflowatthepumpoutlet,andthusthethrombuscanbeprevented.(3)Thecalflivetestsshowthatsomeresidualclotsexistattheinnerwalloftheoutletconnectionbends,whichareanalyzedandexplainedbyCFDtechniquesandthecorrespondingimprovementsareproposed.AllresultsareverifiedbyhydrodynamicperformancetestsandPIVflowfieldtests,andconsistentconclusionsareobtained.

简介：一条即时分析途径被开发在完全扭曲加速的摆动的流动预言表流动运输。途径在一张活动海床上面从速度和集中侧面的指数的近似被导出，并且它特别地考虑阶段铅的因素；阶段落后(即阶段剩余和阶段移动)；加速修正；并且不对称现象在砍应力，粗糙高度，和边界层开发。途径能在一张活动海床上面预言网边界层流动，并且能回复到古典水流带来的碎石模型。即时并且网沉积运输率用途径被学习。在一个向陆的流动阶段的即时沉积运输率能被代表在被证实在阶段剩余与减少在1和5之间变化的速度的力量功能接近。用途径预言的网络沉积运输率用测量数据的可观的数量被验证，并且与存在相比即时并且考虑阶段的一半时期类型模型落后或加速修正。为在完全扭曲加速的摆动的流动的网沉积运输率，阶段剩余不比向陆、近海的加速阶段之间的扭曲加速的边界层差别重要。

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：Theknowledgeofflowregimesisveryimportantinthestudyofatwo-phaseflowsystem.AnewflowregimeidentificationmethodbasedonaProbabilityDensityFunction(PDF)andaneuralnetworkisproposedinthispaper.Theinstantaneousdifferentialpressuresignalsofahorizontalflowwereacquiredwithadifferentialpressuresensor.ThecharactersofdifferentialpressuresignalsfordifferentflowregimesareanalyzedwiththePDF.Then,fourcharacteristicparametersofthePDFcurvesaredefined,thepeaknumber(K1),themaximumpeakvalue(K2),thepeakposition(K3)andthePDFvariance(K4).Thecharacteristicvectorswhichconsistofthefourcharacteristicparametersastheinputvectorstraintheneuralnetworktoclassifytheflowregimes.Experimentalresultsshowthatthisnovelmethodforidentifyingair-watertwo-phaseflowregimeshastheadvantageswithahighaccuracyandafastresponse.Theresultsclearlydemonstratethatthisnewmethodcouldprovideanaccurateidentificationofflowregimes.

简介：Althoughmanyliteratureshavebeenfocusedontheunderneathflowandlossmechanism,veryfewexperimentsandsimulationshavebeendoneundertheengines'representativeworkingconditionsorconsideringtherealcavitystructureasawhole.Thispaperaimsatrealizingthegoalofdesignofefficientturbineandscrutinizingthevelocitydistributioninthevicinityoftherimseal.Withtheaidofnumericalmethod,anumericalmodeldescribingtheflowpatternbothinthepurgeflowspotandwithinthemainstreamflowpathisestablished,fluidmigrationanditsaccompaniedflowmechanismwithintherealisticcavitystructure(withrimsealstructureandconsideringmainstream&secondaryairflow'sinteraction)isusedtoevaluateboththeflowpatternandtheunderneathflowmechanismwithintheinwardrotatingcavity.Meanwhile,theunderneathflowandlossmechanismarealsostudiedinthecurrentpaper.Thecomputationalresultsshowthatthesealingairflow'singestionandejectionarehighlyinterwoundwitheachotherinbothupstreamanddownstreamflowoftherimseal.Boththedownstreamblades'potentialeffectsaswellastheupstreamblades'waketrajectorycanbringabouttheingestionofthehotgasflowwithinthecavity,abruptincreaseofthestaticpressureisbelievedtobethemainreason.Also,theresultsindicatethatsealingairflowejectedthroughtherearcavitywillcauseunexpectedlossneartheoutletsectionofthebladesinthedownstreamoftheHProtorpassages.

简介：Thispaperpresentsanewmethodforrobustandaccurateopticalflowestimation.Thesig-nificanceofthisworkistwofold.Firstly,theideaofbi-directionalschemeisadoptedtoreducethemodelerrorofopticalflowequation,whichallowsthesecondorderTaylor'sexpansionofopticalflowequationforaccuratesolutionwithoutmuchextracomputationalburden;Secondly,thispaperestablishsanewopticalflowequationbasedonLSCM(LocalStructureConstancyModel)insteadofBCM(BrightnessConstancyModel),namelytheopticalflowequationdoesnotactonscalarbutontensor-valued(ma-trix-valued)field,duetothetworeason:(1)structuretensor-valuecontainslocalspatialstructureinformation,whichprovidesusmoreuseablecuesforcomputationthanscalar;(2)localimagestructureislesssensitivetoilluminationvariationthanintensity,whichweakensthedisturbanceofnon-uniformilluminationinrealsequences.Qualitativeandquantitativeresultsforsyntheticandreal-worldscenesshowthatthenewmethodcanproduceanaccurateandrobustresults.

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简介：作者学习Helfrich的L2坡度流动功能，它是功能的描述人的红血房间的形状。为任何i0并且c0，作者在光滑的答案的lifespan上获得更低的界限，它为起始的表面仅仅取决于弯曲的集中。

简介：Thefundamentalsofcohesivepowderconsolidationandflowbehaviourusingareasonablecombinationofparticleandcontinuummechanicsareexplained.Bymeansofthemodel'stiffparticleswithsoftcontacts',theinfluenceofelastic-plasticrepulsioninparticlecontactsisdemonstrated.Withthisasthephysicalbasis,thestationaryyieldlocus,instantaneousyieldlociandconsolidationloci,flowfunctionandcompressionfunctionarepresented.Theflowpropertiesofaverycohesivetitaniananopowder(ds=200nm)areshown.Thesemodelsarausedtoevaluateshearcelltestresultsasconstitutivefunctionsforcomputeraidedapparatusdesignforreliablepowderflow.

简介：Trafficruleisakeyfactoraffectingtrafficflowandsafety.Wedevelopourmodels,includingthecellularautomatatrafficflowmodelaswellasthelinearregressionone,aimingatcalculatingtrafficflowandevaluatingsafetyconditionswithvariedtrafficrules.Then,wethoroughlyinvestigatefourtypesofpathsinafreeway,namelytwostraightlanes,threestraightlanes,ramps,androundaboutsascasestudiesanddiscussthedifferenttrafficrulesascomparison.Theresultsdemonstratethat“Keep-Right-Except-To-Pass”ruleisnotaseffectiveasthefreeruleinpromotingtrafficflow;however,thisruleensuressafetyfordriversbetterthanthefreerule.Additionally,anewtrafficrule,whichsetsdifferentpostedspeedlimitsforadjacentlanes,isproposedtopromotebettertrafficflowwithsafetyrequirementssatisfied.Furthermore,weapplyeffectiverulesandalternatives,leftdrivingnormsaswellasintelligentsystemasextensionandobtainbetterresults.Finally,model’ssensitivityanalysisregardingtoprobabilityofdeceleratingandpostedspeedlimitsprovesthestabilityofourresults.