简介：

简介：TheproblemofacreepingflowofNewtonianfluidextrudedfromaplaneslitoracircularpipe.intheabsenceofgravity,issimulatedsuccessfullybyusingthecontinuous-pressure-elementmethod,thediscontinuous-pressure-elementmethod,theconsistantpenaltymethod,thereducedintegrationpenaltymethodandthemodifiedreducedintegrationpenaltymethodproposedbyOden.Throughcomparisonsbetweenthesemethods,itisconvincedthatthediscontinuous-pressureinterpolationschemesresultinmoreaccuratemassconservationand,consequently,morerapidconvergenceofthefree-surfaceiterationthanthecontinuousonedoes.Thereducedintegrationpenaltymethodcanfurtherreducethecostofcomputationwhileretainingsufficientaccuracyofthesolution.

简介：Theproblemofpenetrativeconvectionwiththecubicandfifth-orderequationsofstateproposedbyMerker,WaasandGrigullisstudied.Bothlinearinstabilityandnonlinearstabilityanalysesareperformedtoassessthesuitabilityoflineartheorytopredictdestabilisationoftheconvection.Thevalidityofboththelinearinstabilityandglobalnonlinearenergystabilitythresholdsaretestedusingthree-dimensionalsimulation.Theresultsshowthatthelinearthresholdaccuratelypredictstheonsetofinstabilityinthebasicsteadystatesolution.

简介：Makingfulluseoffunctionalvariationswithvariabledomainforhandlingboththefreesurfaceandunknownpartofthedamwall,afamilyofvariationalprinciples(VPs)forthehybrid(direct-inverse)problemoffreesurfacespillwayflowundergravityisformulatedintermsofthepotentialfunctionΦ.Thistheoryoffersnewrationalandversatilewaysfordamde-signandasoundtheoreticalbasisfornumericalsolution,e.g.bythefiniteelementmethod(FEM).