简介：NumericalsimulationsoftheflowinthedrafttubeofaFrancisturbinearecarriedoutinordertoelucidatetheeffectsoftangentialvelocityonflowstability.Influenceofthelocationofthemaximumtangentialvelocityisexploredconsideringtheequalityofthetotalenergyattheinletofthedrafttube.Itisfoundthattheamplitudeofthepressurefluctuationdecreaseswhenthelocationofthemaximumofthetangentialvelocitymovesfromthecentretothewallonthecrosssection.Thus,thestabilityoftheflowinthedrafttubeincreaseswiththemovingofthelocationofthemaximumtangentialvelocity.However,therelativehydrauliclossincreasesandtherecoverycoefficientofthedrafttubedecreasesslightly.

简介：Aprecisetangentialcontactdampingmodelisproposed,whichincludesthelateralcontactoftheupper-lowerasperitiesandtheinteractionofadjacentasperities.Theeffectsofthenormalstaticpreload,frequency,andamplitudeoftangentialdisplacementonthetangentialcontactdampingwereanalyzedbysimulation,respectively.Furthermore,theresultsofsimulationareverifiedbyexperiment.Thetangentialcontactdampingofconsideringtheinteractionandlateralcontactofasperityisveryclosetotheexperimentalresults.

简介：由使用包含基本流动的第二个类型(CISK)模型的线性对称的有条件的不稳定性，我们在台风学习在基本流动和mesoscale骚乱之间的相互作用。结果在台风形成的早阶段显示出那，联合行动垂直在底层和CISK基本流动砍推动骚乱很快成长并且向台风的中心移动。同样，骚乱的发展在台风上影响开发和结构。mesoscale骚乱发展和繁殖的分析显示最大值向一只眼睛的中心，风速度增加，和发行量特征弯屈区域行动出现。同样，当台风腐烂时，低级的垂直的风的增加砍便于mesoscale骚乱的发展。接着，这些mesoscale骚乱将向台风提供精力并且让台风再加强。因此，台风有，这能被说可更新或自我修理功能。

简介：Toreproducetheprematureruptureprocessofmetalsheetsubjectedtolaserirradiationwithsubsonicairflow,whichisaninterestingphenomenonobservedintheexperimentsgivenbyLawrenceLivermoreNationalLaboratory,acouplednumericalmodelconsideringtheinteractionandevolutionofmetalelastoplasticdeformationandaerodynamicpressureprofileispresented.Withthethermalelastoplasticconstitutiverelationshipandfailurecriterion,thesimulatedfailuremodesanddynamicruptureprocessarebasicallyconsistentwiththeexperimentalresults,indicatingplasticflowandmultiplefracturingisthemainfailuremechanism.Comparedwiththecaseofnon-airflow,subsonicairflownotonlyacceleratesdeformation,butalsoturnsthebugledeformation,plasticstrainandrupturemodeintoasymmetric.

简介：Aclosed-formsolutionforpredictingthetangentialstressofaninclusionlocatedinmixedmodeⅠandⅡcracktipfieldwasdevelopedbasedontheEshelbyequivalentinclusiontheory.Thenamixedmodefracturecriterion,includingthefracturedirectionandthecriticalload,wasestablishedbasedonthemaximumtangentialstressintheinclusionforbrittleinclusioninducedfracturematerials.Theproposedfracturecriterionisafunctionoftheinclusionfracturestress,itssizeandvolumefraction,aswellastheelasticconstantsoftheinclusionandthematrixmaterial.Thepresentcriterionwillreducetotheconventionaloneastheinclusionhavingthesameelasticbehaviorasthematrixmaterial.Theproposedsolutionsareingoodagreementwithdetailedfiniteelementanalysisandmeasurement.