简介：Intheunderwater-shockenvironment,cavitationoccursnearthestructuralsurface.Thedynamicresponseoffluid-structureinteractionsisinfluencedseriouslybythecavitationeffects.Itisalsothedifficultyinthefieldofunderwaterexplosion.Withthetraditionalboundaryelementmethodandthefiniteelementmethod(FEM),itisdifficulttosolvethenonlinearproblemwithcavitationeffectssubjectedtotheunderwaterexplosion.Tosolvethisproblem,undertheconsiderationofthecavitationeffectsandfluidcompressibility,withfluidvisciditybeingneglected,a3Dnumericalmodeloftransientnonlinearfluid-structureinteractionsubjectedtotheunderwaterexplosionisbuilt.Thefluidspectralelementmethod(SEM)andtheFEMareadoptedtosolvethismodel.AftercomparisonwiththeFEM,itisshownthattheSEMismoreprecisethantheFEM,andtheSEMresultsareingoodcoincidencewithbenchmarkresultsandexperimentresults.Basedonthis,combinedwithABAQUS,thetransientfluid-structureinteractionmechanismofthe3Dsubmergedsphericalshellandshipstiffenedplatessubjectedtotheunderwaterexplosionisdiscussed,andthecavitationregionanditsinfluenceonthestructuraldynamicresponsesarepresented.Thepaperaimsatprovidingreferencesforrelevantresearchontransientfluid-structureinteractionofshipstructuressubjectedtotheunderwaterexplosion.

简介：Analfistulaisoneofthethreegreatestanorectaldiseaseswithahighprevalence.Thetraditionaltreatments(e.g.,surgery)forfistulahavelimitationsduetodamagetotheinternalanalsphincterofpatients.Withrecentadvancesinbiomaterials,treatmentsbasedonbiomaterialfilling(e.g.,scleraproteininjection,fistulaplug)haveemergedasnoveltherapiesforfistula.Theanalfistulaplug(e.g.,basedonsmallintestinalsubmucosa(SIS))hasattractedincreasingattentionbecauseofshorttermhealingrateandbiocompatibility.However,challengesremainforthismethodsuchasplugfallingasobservedinclinics.Toaddressthis,thispaperanalyzesthecaseofSISfallingunderphysiologicalconditionfrommechanicalpointofviewusingANSYSsimulation.Itthenproposesthreenewgeometricalstructuresforfistulaplugandcomparestheirmechanicalbehavior(e.g.,axialstress,reactionofconstraint)withthatofclinicallyusedstructure(coneshape).Basedonthesimulation,itoptimizesthegeometricparametersoffistulaplug.Theapproachdevelopedherecanhelptoimprovethedesignoffistulaplugforbetterclinicaltreatments.

简介：Themethodofnonlinearparabolizedstabilityequations(PSE)isappliedinthesimulationofvortexstructuresincompressiblemixinglayer.Thespatially-evolvingunstablewaves,whichdominatethevortexstructure,areinvestigatedthroughspatialmarchingmethod.Theinstantaneousflowfieldisobtainedbyaddingtheharmonicwavestobasicflow.TheresultsshowthatT-Swavesdonotkeepgrowingexponentiallyasthelinearevolution,theenergytransfertohighorderharmonicmodes,andthatfinallyallharmonicmodesgetsaturatedduetononlinearinteraction.Themeanflowdistortioninducedbythenonlinearinteractionbetweentheharmonicmodesandtheirconjugateharmonicones,makesgreatchangeoftheaverageflowandincreasesthethicknessofmixinglayer.PSEmethodscanwellcapturethetwo-andthree-dimensionallargescalenonlinearvortexstructuresinmixinglayerssuchasvortexroll-up,vortexpairing,andAvortex.