简介:Inthispaperaviscous-inviscidinteractingflowtheory(IFT)isdevelopedforanincompressible,two-dimensionallaminarflow.IFT’smainpointsareasfollows.(1)Byintroducingaconceptofinteractionlay-erwherethenormalmomentumexchangeisdominating,anewthreelayerstructureisestablished.(2)Throughtheconventionalmanipulationsandbyintroducinganinteractionmodel,boththestreamwiseandnormallengthscalesareprovedtobefunctionsofasingleparameterm,whichisrelatedtothestreamwisepressuregradientandReynoldsnumber.(3)Theapproximateequationsgoverningtheflowofeachlayeraswellasthewholeinteractionflowarederived.ThepresentIFTisapplicabletobothattachedandattached-separationbubble-reattachedflows,TheclassicalboundarylayertheoryandTriple-decktheoryareshowntobetwospecialcasesofthepresenttheoryunderm=0and1/4,respectively.FurthermoreIFTprovidesnewdistinctionsofboththenormalandstreamwiselengthscalesforflow-fieldnumericalcomputationandalsogivesanewapproachtodevelopingthesimpli-fiedNavier-Stokes(SNS)equations.
简介:AZener-Strohcrackinteractingwithanedgedislocationisstudied.Thecrackfacesareassumedtobetractionfree.Theapplied'generalizedloading'forcrackistheinitialdisplacementjumpandtheinterventionoftheedgedislocation.Throughdecomposingtheproblemintotwosubsimpleproblems,usingthesuperpositionprinciple,itssolutionisobtained.Todemonstrateboththevalidityofthesolutionanditspotentialapplication,twosimpleexamplesrelatedtothecrackstressintensityfactorsarepre...
简介:Thispaperpresentsacomputationalmodelforthefluiddynamicsinafracturedductilepipeunderhighpressure.Thepressureprofileinfrontofthecracktip,whichisthedrivingsourceofcrackpropagation,iscomputedusinganonlinearwaveequation.Thesolutioniscoupledwithaonedimensionalchokedflowanalysisbehindthecrack.Thesimulationutilizesahighorderoptimizedprefactoredcompact-finitevolumemethodinspace,andlowdispersionanddissipationRunge-Kuttaintime.Asthepipefracturestherapiddepressurizationtakeplaceinsidethepipeandthepropagationofthecrack-inducedwavesstronglyinfluencestheoutflowdynamics.Consistentwiththeexperimentalobservation,themodelpredictstheexpansionwaveinsidethepipe,andthereflectionandoutflowofthewave.Themodelalsohelpscharacterizethepropagationofthecrackdynamicsandfluidflowsaroundthetipofthecrack.