简介：ABSTRACT:Westudytheevolutionofsingleellipticvortexringforinitialaspectratio(AR)=2,4,6.TheincompressibleNavier-Stokesequationsaresolvedbyadealiasedpseudo-spectralmethodwith64~3gridpointsinaperiodiccube.WefindthattherearethreekindsofvortexmotionasARincreasesandvortexbifurcationoccursatacertainAR.Theprocessesofadvection,interaction,anddecayofvortexringareanalyzed.Numericalresultscoincidewithexperimentsandothernumericalsimulations.

简介：ＭＯＤＩＦＩＥＤＩＮＴＥＧＲＡＬ－ＦＡＣＴＯＲＭＥＴＨＯＤＦＯＲＳＴＥＡＤＹＣＯＮＶＥＣＴＩＯＮ－ＤＩＦＦＵＳＩＯＮＥＱＵＡＴＩＯＮＳＸｉｎＸｉａｏ－ｈａｎｇ；ＷａｎｇＨａｏ；ＨｕｏＹｉ（ＤｅｐａｒｔｍｅｎｔｏｆＡｐｐｌｉｅｄＭｅｃｈａｎｉｃｓ，Ｆｕ...

简介：TheflowthroughasinglefractureisnumericallystudiedbymeansoftheFluentSoftware.Theresultsshowthattheroughnessofthefracturesignificantlyaffectsthehydraulicconductivityinthefractureascomparedwiththecubiclawmodelwidelyusedtodescribetheflowbetweentwosmoothparallelplates.Anewmodelisproposedinthispaper,thenon-symmetricsinusoidalfracturemodel,tosimulatetheflowinarealfracture.Thismodelinvolvestwosinusoidal-varyingwallswithdifferentphasestoreplacetheflatplanesinthecubiclawmodel.Therelationshipsbetweentheeffectivehydraulicaperturesandthephaseretardationfordifferentrelativeamplitudesandwavelengthsarenumericallyinvestigated.Asimpleexpressionoftheeffectivehydraulicapertureofthefractureisobtained,togetherwiththelawoftheeffectivehydraulicapertureagainsttheamplitude,thephaseretardationandthewavelengthoftwosinusoidal-varyingwalls.

简介：Fluidcharacteristicsofarotarywingheatmeterwithsingle-channelwerestudiedthroughthereticalanalysis,numericalsimulationandexperiments.Theobtainedresultsshowthatthenumberofvanescanobviouslyinfluencetheheatmeter,butthewatertemperatureseldominfluencethemeter,andtheoptimalnumberofvaneis6-8.

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简介：Basedonvariationaladjointmethods,theoreticalanalysesandnumericalexperimentsareperformedforretrievalsoftwo-dimensionalwindsandrelatedparametersfromsingle-Dopplerradardatainpolarcoordinates.Inthemethod,thereflectivityconservationequationisusedasthegoverningequationandthemasscontinuityequationasaweakconstraint.Atthesametime,thestablefunctionalofregularizationandbackgroundfieldarealsointroducedinthecostfunctional.Basedontheidealexperimentswithartificialdata,realtwo-dimensionalwindfieldsareretrievedwithlow-altitudedatafromtheNanjingDopplerRadarStation,andtheresultsareencouragingandpromising.