简介:Throughaseriesofmodeltests,thewaveforcesonhorizontalandinclinedcircularcylindersaremeasuredandanalyzed.BasedonMorisonEquationandStokessecondorderwavetheory,therelationshipbetweenthehydrodynamicforcecoefficientswithKCnumberandsub-mergedwaterdepthaswellforhorizontalcylindersareanalyzed,alsotherelationshipbetweenthehydrodynamicforcecoefficientswithKCnumber,inclinedangleandtheeffectofwaterfreesurfaceaswellfortheinclinedcylindersareinvestigated.
简介:Bytheuseofthe3/2powerlawpresentedbyTobacombinedwiththesignificantwaveenergybalanceequationforwindwave,windwavegrowthatalimitedfetchisanalyticallyinvestigated.Thenewwindwavegrowthrelations(WWGRs)areanalyticallyderivedwithshelteringcoefficientandwinddragcoefficientasparameters.Thegeometricalaverageofobservationalvaluesofshelteringcoefficientandthearithmeticaverageofobservationalvaluesofwinddragco-efficientareappliedtodeterminethenewWWGRs.ComparisonswithexistingempiricalWWGRsaremade.
简介:Inthispaperthemodelling,analysisandoptimizationofmillimeterwaveoscillatorsareinvestigatedbyusingtheafrequency-domainharmonicbalancetechnique(FDHB),wheretheexternal-circuitimpedanceslookingoutsidefromtheactivedevicearecalculatedwithacombinedtechniqueofmodesexpansion,Galerkin,andcollocationmethods.Theoptimizationresultsareinagreementwiththeexperimentalones,whichshowthereliabilityofthepresentedmodelandoptimization.
简介:SomeofthemainprogressontheinvestigationofthemechanismofthewaveformationinexplosiveweldingattheInstituteofMechanicsissummarizedandotters’previousworksarere-viewed.OursystematicexperimentsandanalysisdonotsubstantiatethetheoryofwaveformationbasedonKarmanvortex-streetanalogyorHelmholtzinstability.Onthecontrary,theyshowthatmateri-alstrengthinsensitivetostrainrateplaysanimportantrole.Asimplehydro-plasticmodelispresentedtoexplainthemainfeaturesregardingtheinterracialwaveformationandtoestimatethemagnitudeofwavelength.Theresultisinbroadagreementwithexperiment.
简介:Thepurposeofthepresentpaperistocallforattentiontothefollowingquestion:Whichoftheinitialdata(nonsmall)admitglobalsmoothsolutionstotheCauchyproblemfornonlinearwaveequations.Afewcasesandexamplesaresketched,showingthatthegeneralanswerofthisquestionmaybequitecomplicated.
简介:AsimulationonthepropagationoflowerhybridwaveinEASTisconducted.Raytracing,evolutionoftheparallelrefractiveindex,andpowerdepositionprofilesinaD-shapedconfigurationwerecalculated.Resultsshowthatwavepropagationisaffectedbytheplasmacurrent,density,magneticfield,andpowerspectrum,etc.leadingtoadifferentpowerdeposition.ThisishelpfulinunderstandingtheLHCDexperimentsonEAST.
简介:在一个thermoacoustic声波发电机的摆动的流动被描述。thermoacoustic声波发电机在thermoacoustic设备起一个重要作用。在工作液体的工作液体和栈,加速和减速之间的热交换并且粘滞在栈并且在回声试管影响的磨擦损失thermoacoustic声波生成器的性能。特别地,摆动的流动显著地影响在工作液体和栈之间的热交换机制。在压力和速度的时间的变化是在回声试管内的正弦曲线。流动就在试管插头后面形成一口摆动的喷气,并且在回声试管外面下游地远变得断断续续。0.63R的无限制的修正,也就是说尽管有在试管插头外面,被速度大小证实并且流动,摆动的流动特征下游地被维持的区域可视化。另外,他们几乎等于听觉的理论结果。关键词thermoacoustic现象-声波生成器-摆动的流动CLC数字TK11.4
简介:""Mensaytheyhatetoshop,""saysZhukin,CityUniversityofNewYorkSociology(社会学)professor.""Yetwhenyouaskthemdeeperquestions,itturnsoutthattheyliketoshop.Mengenerallyliketoshopforbooks,musicandhardware.Butifyouaskthemabouttheshoppingtheydoforbooksormusic,they'llsay,'Well,that'snotshopping.That'sresearch.'""
简介:Romanticismisanimportantstageintheevolutionofman’sself-consciousness.Itshowsnewinterestinandnewconcernwithmanandnature.Wordsworthiswell-knownasanaturepoet.Thethemeofhumanmindandnatureinhispoemshaslongattractedreaders’attention.However,hedoesnotindulgeinnatureitselfbuttakesitasconsolationandinspirationforhumankind.Inordertohighlightthepoet’sconcernwithhumanmind,thepresentpaperchoosestoexploreWordsworth’sconcernwithchildren’smind,basedontheanalysisofWordsworth’sThePreludeandmanyofhispoemsaboutchildren.
简介:Inthispaper,anumericalmodelof2Dweaklycompressiblesmoothedparticlehydrodynamics(WCSPH)isdevelopedtosimulatetheinteractionbetweenwavesandthinstructures.Anewcolordomainparticle(CDP)techniqueisproposedtoovercomedifficultiesofapplyingtheghostparticlemethodtothinstructuresindealingwithsolidboundaries.Thenewtechniquecandealwithzero-thicknessstructures.Toapplythisenforcingtechnique,thecomputationalfluiddomainisdividedintosubdomains,i.e.,boundarydomainsandinternaldomains.Acolorvalueisassignedtoeachparticle,andcontainstheinformationofthedomainsinwhichtheparticlebelongstoandtheparticlescaninteractwith.Aparticle,nearbyathinboundary,ispreventedfrominteractingwithparticles,whichshouldnotinteractwithontheothersideofthestructure.Itispossibletomodelthinstructures,orthestructureswiththethicknessnegligiblewiththistechnique.TheproposedWCSPHmoduleisvalidatedforastillwatertank,dividedbyathinplateatthemiddlesection,withdifferentwaterlevelsinthesubdomains,andisappliedtosimulatetheinteractionbetweenregularwavesandaperforatedverticalplate.Finally,thecomputationiscarriedoutforwavesandsubmergedtwin-horizontalplateinteraction.Itisshownthatthenumericalresultsagreewellwithexperimentaldataintermsofthepressuredistribution,pressuretimeseriesandwavetransmission.
简介:概括波浪活动密度,被定义为三维的涡度向量不安和一般潜在的温度不安的坡度的生产的绝对值,被介绍,它的波浪活动法律在笛卡儿的坐标被导出。在agoestrophic和nonhydrostatic构造了动态框架,概括波浪活动法律可能是适用的诊断导致重降雨的mesoscale天气系统。概括波浪活动密度和波浪活动流动分叉与客观分析数据被计算在重降雨的区域上调查波浪活动的字符。为与重降雨联系的骚乱负责的主要动态过程也被分析。概括波浪活动密度密切被相关到观察6-h,这被显示出积聚的降雨。这显示波浪活动或骚乱是明显的在上正面并且乍见陆地台风在中间、更低的对流层的重降雨的区域。为乍见陆地台风雨线,概括波浪活动流动分叉的部分,表示在基本状态的气旋的发行量之间的相互作用乍见陆地,台风和mesoscale飘动,是为概括波浪活动的进化负责的主要动态过程密度。
简介:Pierson-MoskowitzSpectrum,JONSWAPSpectrumaswellasBretschneider-MitsuyasuSpectrumareusedinthispaperforanalyzingtheinfluenceofwaveenergydirectionalspreadonrefractionofwavespectrumduetobothcurrentandtopographyofseabed.Theauthor’scalculationindicatesthatsuchkindinfluenceonthecharacteristicvalueofwaveheightaswellastheaveragedirectionofwaveenergypropagationcannotbeignored.
简介:Forthesimulationofthenonlinearwavepropagationincoastalareaswithcomplexboundaries,anumericalmodelisdevelopedincurvilinearcoordinates.Inthemodel,theBoussinesq-typeequationsincludingthedissipationtermsareemployedasthegoverningequations.Inthepresentmodel,thedependentvariablesofthetransformedequationsarethefreesurfaceelevationandtheutilityvelocityvariables,insteadoftheusualprimitivevelocityvariables.TheintroductionofutilityvelocityvariableswhicharetheproductsofthecontravariantcomponentsofthevelocityvectorandtheJacobimatrixcanmakethetransformedequationsrelativelyconcise,thetreatmentoflateralboundaryconditionseasierandthedevelopmentoftheprogramsimpler.Thepredictor-correctormethodandfive-pointfinite-differenceschemeareemployedtodiscretizethetimederivativesandthespatialones,respectively.Thenumericalmodelistestedforthreecases.Itisfoundthatthenumericalresultsareingoodagreementwiththeanalyticalresultsandexperimentaldata.
简介:Inthispaper,twofinitedifferenceschemesarepresentedforinitial-boundaryvalueproblemsofRegularizedLong-Wave(RLW)equation.Theyallhavetheadvantagesthattherearediscreteenergieswhichareconserved.ConvergenceandstabilityofdifferencesolutionswithorderO(h2+τ2)areprovedintheenergynorm.Numericalexperimentresultsdemonstratetheeffectivenessoftheproposedschemes.
简介:Basedonthe1stordercnoidalwavetheory,thewavediffractionaroundthepiergroupinshallowwaterisstudiedinthispaper.Theformulasforcalculatingthenonlinearwaveforcesarealsopresentedhere.Inordertoverifythetheoreticalresults,modeltestsareconductedinthewaveflumeinTheStateKeyLaboratoryofCoastalandOffshoreEngineeringlocatedinDalianUniversityofTechnology.TherangeofthewaveparametersintheexperimentsischaracteristicwaveperiodTg/d1/2=8.08-22.86,characteristicwaveheightH/d=0.10.45.Theresultsobtainedfromtheexperimentsagreewiththetheoreticalresultsquitewell.Itisshownthat,inshallowwaterthenonlinearwaveforcesactingonapiergrouparegreaterthanthosecalculatedbylinearwavetheory,thevalueofincrementinwaveforceincreaseswiththeincreasesofthenonlinearityofthewave.Inthewaverangestudiedinthispaper,thenonlinearwaveforcecanreachover4timestheforcecalculatecdbylinearwavetheory.Thus,itissuggestedthat,whenTg/d1/2>8,thewaveforceonthepiersinthepiergroupinshallowwatershouldbecalculatedbyusingthecnoidalwavetheory.
简介:Wavepropagationintwo-dimensionalhierarchicalhoneycombstructureswithtwoorderhierarchyisinvestigatedbyusingthesymplecticalgorithm.Byapplyingthevariationalprincipletothedualvariables,thewavepropagationproblemistransformedintoatwo-dimensionalsymplecticeigenvalueproblem.Thebandgapsandspatialfilteringphenomenaareexaminedtofindthestopbandsanddirectionalstopbands.Specialattentionisdirectedtotheeffectsoftherelativedensityandthelengthratioonthebandgapsandphaseconstantsurfaces.Thisworkprovidesnewopportunitiesfordesigninghierarchicalhoneycombstructuresinsoundinsulationapplications.