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简介：Inthispaperlargeeddysimulationofthefullydevelopedturbulentflowinacurvedchanneliscarriedout.ThecomputationalresultsarepresentedandcomparedwiththeexperimentalresultsofEskinaziandYeh.ItisshownthatthenumericalresultsofthepresentLESarereliableandtheinfluenceofthecurvatureontheturbulencefeatureiscorrectlyrevealed.

简介：Lagrangian-Eulerianformulationsbasedonageneralizedvariationalprincipleoffluid-solidcouplingdynamicsareestablishedtodescribeflow-inducedvibrationofastructureundersmalldeformationinanincompressibleviscousfluidflow.Thespatialdiscretizationoftheformulationsisbasedonthemulti-linearinterpolatingfunctionsbyusingthefiniteelementmethodforboththefluidandsolidstructures.Thegeneralizedtrapezoidalruleisusedtoobtainapparentlynon-symmetriclinearequationsinanincrementalformforthevariablesoftheflowandvibration.Thenonlinearconvectivetermandtimefactorsarecontainedinthenon-symmetriccoefficientmatrixoftheequations.Thegeneralizedminimumresidual(GMRES)methodisusedtosolvetheincrementalequations.AnewstablealgorithmofGMRES-Hughes-Newmarkisdevelopedtodealwiththeflow-inducedvibrationwithdynamicalfluid-structureinteractionincomplexgeometries.Goodagreementbetweenthesimulationsandlaboratorymeasurementsofthepressureandbladevibrationaccelerationsinahydroturbinepassagewasobtained,indicatingthattheGMRES-Hughes-Newmarkalgorithmpresentedinthispaperissuitablefordealingwiththeflow-inducedvibrationofstructuresundersmalldeformation.

简介：Inthispaper,afullythird-orderaccurateprojectionmethodforsolvingtheincompressibleNavier-Stokesequationsisproposed.Toconstructthescheme,acontinuousprojectionprocedureisfirstlypresented.Wethenderiveasufficientconditionforthecontinuousprojectionequationstobetemporallythird-orderaccurateapproximationsoftheoriginalNavier-Stokesequationsbymeansofthelocaltruncation-error-analysistechnique.Thecontinuousprojectionequationsarediscretizedtemporallyandspatiallytothird-orderaccuracyonthestaggeredgrids,resultinginafullythird-orderdiscreteprojectionscheme.Thepossibilitytodesignhigher-orderprojectionmethodsisthusdemonstratedinthepresentpaper.Aheuristicstabilityanalysisisperformedonthisprojectionmethodshowingtheprobabilityofitsbeingstable.Thestabilityofthepresentschemeisfurtherverifiedthroughnumericaltests.Thethird-orderaccuracyofthepresentprojectionmethodisvalidatedbyseveralnumericaltestcases.