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500 个结果
  • 简介:Throughaseriesofmodeltests,thewaveforcesonhorizontalandinclinedcircularcylindersaremeasuredandanalyzed.BasedonMorisonEquationandStokessecondorderwavetheory,therelationshipbetweenthehydrodynamicforcecoefficientswithKCnumberandsub-mergedwaterdepthaswellforhorizontalcylindersareanalyzed,alsotherelationshipbetweenthehydrodynamicforcecoefficientswithKCnumber,inclinedangleandtheeffectofwaterfreesurfaceaswellfortheinclinedcylindersareinvestigated.

  • 标签: WAVE FORCE HYDRODYNAMICS inclined CYLINDER HORIZONTAL
  • 简介:Bytheuseofthe3/2powerlawpresentedbyTobacombinedwiththesignificantwaveenergybalanceequationforwindwave,windwavegrowthatalimitedfetchisanalyticallyinvestigated.Thenewwindwavegrowthrelations(WWGRs)areanalyticallyderivedwithshelteringcoefficientandwinddragcoefficientasparameters.Thegeometricalaverageofobservationalvaluesofshelteringcoefficientandthearithmeticaverageofobservationalvaluesofwinddragco-efficientareappliedtodeterminethenewWWGRs.ComparisonswithexistingempiricalWWGRsaremade.

  • 标签: WIND WAVE WIND WAVE GROWTH RELATION
  • 简介:Inthispaperthemodelling,analysisandoptimizationofmillimeterwaveoscillatorsareinvestigatedbyusingtheafrequency-domainharmonicbalancetechnique(FDHB),wheretheexternal-circuitimpedanceslookingoutsidefromtheactivedevicearecalculatedwithacombinedtechniqueofmodesexpansion,Galerkin,andcollocationmethods.Theoptimizationresultsareinagreementwiththeexperimentalones,whichshowthereliabilityofthepresentedmodelandoptimization.

  • 标签: MILLIMETER wave OSCILLATOR External-circuit IMPEDANCES Large-signal
  • 简介:研究被做克服在一条航道与一艘轮船的自动驾驶系统联系的传统的问题。一艘轮船有波浪骚乱的动态模型被造;一个波浪过滤器借助于一个扩大状态观察员(ESO)被设计。模型从有颜色的噪音贿赂的出发大小估计了低频率运动部件,因此前后的驾驶由高频率波浪骚乱引起了被避免。同时,一个柔韧的自动驾驶仪系统,由可变结构控制理论设计了,被介绍。在波浪过滤器工作很好的危险的海地位表演完成的模拟结果;自动驾驶仪有强壮的坚韧性到环境骚乱;模型不安,;更重要地,rudder调整的频率显著地被减少。

  • 标签: 滤波器 自动驾驶仪 变结构控制 波状扰动 船舶
  • 简介:SomeofthemainprogressontheinvestigationofthemechanismofthewaveformationinexplosiveweldingattheInstituteofMechanicsissummarizedandotters’previousworksarere-viewed.OursystematicexperimentsandanalysisdonotsubstantiatethetheoryofwaveformationbasedonKarmanvortex-streetanalogyorHelmholtzinstability.Onthecontrary,theyshowthatmateri-alstrengthinsensitivetostrainrateplaysanimportantrole.Asimplehydro-plasticmodelispresentedtoexplainthemainfeaturesregardingtheinterracialwaveformationandtoestimatethemagnitudeofwavelength.Theresultisinbroadagreementwithexperiment.

  • 标签: INTERFACE WAVES INSTABILITY of INTERFACE EXPLOSIVE
  • 简介:AsimulationonthepropagationoflowerhybridwaveinEASTisconducted.Raytracing,evolutionoftheparallelrefractiveindex,andpowerdepositionprofilesinaD-shapedconfigurationwerecalculated.Resultsshowthatwavepropagationisaffectedbytheplasmacurrent,density,magneticfield,andpowerspectrum,etc.leadingtoadifferentpowerdeposition.ThisishelpfulinunderstandingtheLHCDexperimentsonEAST.

  • 标签: 传播模拟 低混杂波 电流驱动实验 沉积剖面 折射率变化 射线追踪
  • 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

  • 标签: 热声现象 声波发电 摆动流 热交换
  • 简介:""Mensaytheyhatetoshop,""saysZhukin,CityUniversityofNewYorkSociology(社会学)professor.""Yetwhenyouaskthemdeeperquestions,itturnsoutthattheyliketoshop.Mengenerallyliketoshopforbooks,musicandhardware.Butifyouaskthemabouttheshoppingtheydoforbooksormusic,they'llsay,'Well,that'snotshopping.That'sresearch.'""

  • 标签: SHOPPING and SHOPPING like about WHEN
  • 简介:Romanticismisanimportantstageintheevolutionofman’sself-consciousness.Itshowsnewinterestinandnewconcernwithmanandnature.Wordsworthiswell-knownasanaturepoet.Thethemeofhumanmindandnatureinhispoemshaslongattractedreaders’attention.However,hedoesnotindulgeinnatureitselfbuttakesitasconsolationandinspirationforhumankind.Inordertohighlightthepoet’sconcernwithhumanmind,thepresentpaperchoosestoexploreWordsworth’sconcernwithchildren’smind,basedontheanalysisofWordsworth’sThePreludeandmanyofhispoemsaboutchildren.

  • 标签: ROMANTICISM WORDSWORTH children’s MIND
  • 简介:AnIntroductiontotheNewBook-GEOSTROPHICWAVECIRCULATIONS¥Yong.L.McHallDept.ofEarth,AtmosphericandPlanetarySciences,MITPublished...

  • 标签: WAVE CIRC
  • 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.

  • 标签: SPH CDP THIN plate wave–structure INTERACTION
  • 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。

  • 标签: 台风雨 活性 诊断 中尺度天气系统 温度扰动 动力学过程
  • 简介:Pierson-MoskowitzSpectrum,JONSWAPSpectrumaswellasBretschneider-MitsuyasuSpectrumareusedinthispaperforanalyzingtheinfluenceofwaveenergydirectionalspreadonrefractionofwavespectrumduetobothcurrentandtopographyofseabed.Theauthor’scalculationindicatesthatsuchkindinfluenceonthecharacteristicvalueofwaveheightaswellastheaveragedirectionofwaveenergypropagationcannotbeignored.

  • 标签: WAVE SPECTRUM WAVE REFRACTION directional WAVES
  • 简介:Forthesimulationofthenonlinearwavepropagationincoastalareaswithcomplexboundaries,anumericalmodelisdevelopedincurvilinearcoordinates.Inthemodel,theBoussinesq-typeequationsincludingthedissipationtermsareemployedasthegoverningequations.Inthepresentmodel,thedependentvariablesofthetransformedequationsarethefreesurfaceelevationandtheutilityvelocityvariables,insteadoftheusualprimitivevelocityvariables.TheintroductionofutilityvelocityvariableswhicharetheproductsofthecontravariantcomponentsofthevelocityvectorandtheJacobimatrixcanmakethetransformedequationsrelativelyconcise,thetreatmentoflateralboundaryconditionseasierandthedevelopmentoftheprogramsimpler.Thepredictor-correctormethodandfive-pointfinite-differenceschemeareemployedtodiscretizethetimederivativesandthespatialones,respectively.Thenumericalmodelistestedforthreecases.Itisfoundthatthenumericalresultsareingoodagreementwiththeanalyticalresultsandexperimentaldata.

  • 标签: 数值模型 曲线坐标 非线性波 BOUSSINESQ型方程 波传播 有限差分格式
  • 简介:Inthispaper,twofinitedifferenceschemesarepresentedforinitial-boundaryvalueproblemsofRegularizedLong-Wave(RLW)equation.Theyallhavetheadvantagesthattherearediscreteenergieswhichareconserved.ConvergenceandstabilityofdifferencesolutionswithorderO(h2+τ2)areprovedintheenergynorm.Numericalexperimentresultsdemonstratetheeffectivenessoftheproposedschemes.

  • 标签: RLW方程 微分概形 守恒 收敛
  • 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.

  • 标签: CYLINDER PIER GROUP WAVE FORCE SHALLOW
  • 简介:Wavepropagationintwo-dimensionalhierarchicalhoneycombstructureswithtwoorderhierarchyisinvestigatedbyusingthesymplecticalgorithm.Byapplyingthevariationalprincipletothedualvariables,thewavepropagationproblemistransformedintoatwo-dimensionalsymplecticeigenvalueproblem.Thebandgapsandspatialfilteringphenomenaareexaminedtofindthestopbandsanddirectionalstopbands.Specialattentionisdirectedtotheeffectsoftherelativedensityandthelengthratioonthebandgapsandphaseconstantsurfaces.Thisworkprovidesnewopportunitiesfordesigninghierarchicalhoneycombstructuresinsoundinsulationapplications.

  • 标签: 分层蜂窝结构 波传播 辛分析 矩阵特征值问题 对偶变量 变分原理