简介：Inthispaper,thewaves’breakingintheleewavesissuccessfullysimulatedbytheatmosphericmesoscalenumericalmodelwithasecond-ordertur-bulentclosure.Itisfurtherprovedthattheturbulenceinthewave-breakingregionplaystheroleofintensemixingfortheaveragefield,whichleadstothetrappingofupwardpropagatingwavesandthuspromotesthedevelopmentofthedownslopewind.Theturbulentstructureinthewave-breakingregionisdiscussedandthefol-lowingconclusionsareobtained:(1)Inthewave-breakingregion,theturbulentheatfluxestransferfrominsidetooutsideandtheturbulentmomentumfluxestransferfromoutsidetoinside.(2)Inthewave-breakingregion,theturbulentenergymainlycomesfromthewindshearandthebuoyancypromotestheturbulentdevelopmentonlyinpartoftheregion.(3)Intheupperpartofthewave-breakingregion,theturbulentmomentumfluxesbehaveasacounter-gradienttransfer.(4)Theturbulentmixinginthewave-breakingregionisnon-local.

简介：Aunifiedperturbationtheoryisdevelopedhereforcalculatingsolitarywavesofallheightsbyseriesexpansionofbaseflowvariablesinpowersofasmallbaseparametertoeighteenthorderfortheone-parameterfamilyofsolutionsinexactform,withallthecoefficientsdeterminedinrationalnumbers.Comparativestudiesarepursuedtoinvestigatetheeffectsduetochangesofbaseparameterson(i)theaccuracyofthetheoreticallypredictedwavepropertiesand(ii)therateofconvergenceofperturbationexpansion.Twoimportantresultsarefoundbycomparisonsbetweenthetheoreticalpredictionsbasedonasetofparametersseparatelyadoptedforexpansioninturn.First,theaccuracyandtheconvergenceoftheperturbationexpansions,appraisedversustheexactsolutionprovidedbyanearlierpaper[1]asthestandardreference,arefoundtodepend,quitesensitively,onchangesinbaseparameter.Theresultingvariationsinthesolutionarephysicallydisplayedinvariouswavepropertieswithdifferencesfounddependentonwhichproperty(e.g.thewaveamplitude,speed,itsprofile,excessmass,momentum,andenergy),onwhatrangeinvalueofthebase,andontherankoftheordernintheexpansionbeingaddressed.Secondly,regardingconvergence,thepresentperturbationseriesisfounddefinitelyasymptoticinnature,withtherelativeerrorδ(n)(therelativemean-squaredifferencebetweensuccessiveordersnofwaveelevations)reachingaminimum,δm,ataspecificorder,n=nm,bothdependingonthebaseadopted,e.g.n=11-12basedonparameterα(waveamplitude),nm,β=15onβ(amplitude-speedsquareratio),andnm.∈=17on∈(wavenumbersquared).Theasymptoticrangeisbroughttocompletionbythehighestorderofn=18reachedinthiswork.

简介：Solitarywavesinrelativisticelectromagneticplasmasareobtainednumerically.Thelongitudinalmomentumofelectronshasbeentakenintoaccountintheproblem.Itisfoundthatinthemovingframewithelectromagneticfieldpropagatingthesolitarywavescanexistinbothcases,wherethevectorpotentialfrequencyislargerorsmallerthantheplasmacharacteristicfrequency.

简介：Asystematicprocedureisproposedforobtainingsolutionsforsoli-tarywavesinstratifiedfluids.Thestratificationofthefluidisassumedtobeexpo-nentialorlinear.Itscomparisonwithexistingresultsforanexponentiallystratifiedfluidshowsagreement,anditisfoundthatfortheoddseriesofsolutionsthedirec-tionofdisplacementofthestreamlinesfromtheirasymptoticlevelsisreversedwhenthestratificationischangedfromexponentialtolinear.Finallytheinteractionofsolitarywavesisconsidered,andtheKorteweg-deVriesequationandtheBoussinesqequationarederived.Thustheknownsolutionsoftheseequationscanberehedupontoprovidetheanswerstotheinteractionproblem.

简介：Inliterature,nonlineartravelingwavesinelasticcircularrodshaveonlybeenstudiedbasedonsinglepartialdifferentialequation(pde)models,andhereweconsidersuchaproblembyusingamoreaccuratecoupled-pdemodel.WederivetheHamiltonianfromthemodelequationsforthelongfinite-amplitudewaveapproximation,analyzehowthenumberofsingularpointsofthesystemchangeswiththeparameters,andstudythefeaturesofthesesingularpointsqualitatively.Variousphysicallyacceptablenonlineartravelingwavesarealsodiscussed,andcorrespondingexamplesaregiven.Inparticular,wefindthatcertainwaves,whichcannotbecourltedbythesingle-equationmodel,canarise.

简介：Anewapproachtothetheoryoffinite-amplitudestandingwavesinproposed,andfoumulasofsteadywaveformsarederivedfromthefundamentalequationsofhydrodynamios,asanendeavortosettlethelong-timedisputablesituation.

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简介：Basedonthetheoryofelasticdynamics,thescatteringofelasticwavesanddynamicstressconcentrationinfiber-reinforcedcompositewithinterfacesarestudied.Analyticalexpressionsofelasticwavesindifferentmediumareasarepresentedandananalyticmethodofsolvingthisproblemisestablished.Themodecoefficientsaredeterminedbymeansofthecontinuousconditionsofdisplacementandstressontheboundaryoftheinterfaces.Theinfluenceofmaterialpropertiesandstructuralsizeonthedynamicstresscon-centrationfactorsneartheinterfacesisanalyzed.Itindicatesthattheyhaveagreatinfluenceonthedynamicpropertiesoffiber-reinforcedcomposite.Asexamples,numericalresultsofdynamicstressconcentrationfac-torsneartheinterfacesarepresentedanddiscussed.Thispaperprovidesreliabletheoreticalevidenceforthestudyofdynamicpropertiesinfiber-reinforcedcomposite.

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简介：Aboundaryintegralequationmethodisappliedtothestudyoftheinteractionofplaneelasticwaveswithaperiodicarrayofcollinearinplanecracks.Numericalresultsarepresentedforthedynamicstressin-tensityfactors.Theeffectsofthewavetype,wavefrequency,waveincidenceangle,andcrackspacingonthedynamicstressintensityfactorsareanalyzedindetail.

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简介：Understandingtheimprovedconfinementstillremainoneofthemajorgoalsofthetokamakfusionprogram,andmostimportantresearchschemesintokamakrelatetoplasmaconfinementwithauxiliaryheatingandcurrentdrive.Whenauxiliarypowerexceedsathresholdvalue,L-Htransitionwilltakeplace.Theoretiesandexperimentsshowthatthistransitionisconcernedwiththeshearedplasmapoloidalrotationintheedge.Whenanexternalelectromagneticwaveisinjectedintoplasmabyantenna,

简介：Wepresentthepropagationofcylindricalwavesinthemediawhosepermittivityvarieswithtimeabruptlyorcontinuously.Bythemethodofvariableseparation,wederivethegeneralexpressionofelectricfieldofTM-polarizedwavesintwo-dimensionalspacewithexcitationofanypointatanytime.Withthisexpression,thesolutionforaspatiallyandtemporallydistributedsourcecanbeobtainedtheoretically.Thefocusingofreflectedwavesinthecrosssectionisshownwhenthemediaundergoesasuddenorcontinuouschange.Thewavepropagationintime-invariantmediacanbeconsideredasaspecialcaseofthemediaunderexponentialvariance.

简介：Thepropagationofmultipolemodalwavesalongthewell-axisinafluid-filledboreholesurroundedbyelasticandnonelastic,infiniteandfiniteformationisanalysedbyusingthewaveequations.Thephasevelocitydispersionandtheexcitationcurvesarenumericallycalculated.Thewaveformsexcitedbyattenuatingburstsarealsocalculated.Themeasurementswithlong-spaceddipoletransducersmadeofPZTthindisksvibratinginbendingmodearecarriedoutinaconcretemodelwellandtheexperimentalresultsarecomparedwiththetheoreticalresults.

简介：AgeneralsolutionoftheBoussinesqequationispresentedwhichsolvestheproblemofinteractionofanynumberofright-goingandleft-goingsolitarywaves.Thesolutionreliesontheexactsolu-tionofGardner,Greene,Kruskal,andMiura(1967),andhasthesamedegreeofaccuracyasthatsolution,buthasawiderscopeofapplication.Itismuchsimplerthan,butasaccurateas,Hirota’sexactsolu-tion(1973)oftheBoussinesqequation,towhichthepresentsolutioniscomparedforthesimplestcaseoftwosolitarywavesinhead-oncollision.

简介：Numericalinvestigationonthedynamicmechanismhasbeenmadeforanalbatrosstoflyeffectivelynearseasurface.Emphasizingontheeffectoftheseawave,thealbatrossissimplifiedasatwo-dimensionalairfoilandthepanelmethodbasedonthepotentialflowtheoryisemployedtocalculatethewaveeffectontheaerodynamicforces.Thenumericalresultshavebeenpresentedforthestatesofflyingatdifferentconstantspeedswithconstantheightsabovesealevel,andflyingatdifferentconstantspeedswiththecombinedoscillationsofpitchingandfreeheaving.Itisshownthatthealbatrossflightefficiencydependsonnotonlythespeedandheightofflightbutalsothewaveamplitudeandthewavelength.Thealbatrossbenefitsbywaveeffecttogetthrust,soastoreducetheresistanceinthecircumstancesofroughsea.

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简介：Anumericalmethodofsolvingacousticwavescatteringpnbleminfluidsisdescribed.Radiationboundarycondition(RBC)obtainedbyfactorizationmethodofHelmholtzequationisappliedtotransformingtheexteriorboundaryvalueprobleminunboundedregionintooneinafiniteregion.CombinedwithRBCandscatterersurfaceboundarycondition,Helmholtzequationissolvednumericallybythefinitedifferencemethod.ComputationalresultsforsphereandprolatespheroidalscatterersareinexcellentagreementwitheigenfunctionsolutionsandmuchbetterthantheresultsofOSRCmethod.