学科分类
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9 个结果
  • 简介:Hydrodynamiccharactersonahorizontal,thin,rigidplatelocatedbeneaththefreesurfacearenumericallyinvestigated.Assumingalinear,time-harmonicpotentialflowandutilizingGreenidentity,thegoverningLaplaceequationcanbesimplifiedintoFredholmintegralequationofthesecondkind.Supposinglinear-orderdiscontinuouselementsalongintersectingverticalboundaries,andbyuseoftheboundaryelementmethod,numericalsolutionaboutsourcestrengthdistributionontheplatecanbechangedintoaseriesofalgebraicequations.The3DGreenfunctionisintroducedtosetuptheintegralequations,andtheGMRESsolverisperformedforsolvingthelargedenselinearsystemofequations.Theadded-mass,dampingforceandexcitingforceareevaluateddirectlyfromtheequations.Itisfoundthattheadded-masscoefficientbecomesnegativeforarangeoffrequencieswhentheplateissufficientlyclosetothefreesurface.

  • 标签: SUBMERGED plate Dreen function Added mass
  • 简介:Inthispaper,usingHolland’smethod,theeffectofthehorizontalstructureoftropicalcyclonesontheirmotionisinvestigated.The"characteristicradius",r0characterizedasthehorizontalstructureofatropicalcyclone,inwhichmandparetheparametersofthevortex,hasbeenfoundbytheauthor.Andthenithasbeenshownthatthereisbutone"characteristicradius"foreachcyclonewithhorizontalstructure.Twodirectanalyticsolutionsfortheuniformandnon-uniformbasicflowsinsteadysituationsarepresentedwithrcResultsshowthatthechangeinthehorizontalstructureofthetropicalcycloneitselfwillhaveobviouseffectonthecyclonemotion,onbothitsdirectionandspeed.Thereforeitmustbeconsideredintheresearchonthetropicalcyclonemotion.

  • 标签: tropical CYCLONE vortex radius deviation NORTHWARD
  • 简介:Theinteractionbetweenwaveandhorizontalandverticalplatesisinvestigatedbytheboundaryelementmethod,andtherelationsofwaveexcitingforcewithplatethickness,submergenceandlengthareobtained.Itisfoundthat:1)Theefficientwaveexcitingforceexistswhileplatesubmergenceislessthan0.5m,andtheplateisverythinwithorderO(0.005m).2)Themaximumheavewaveexcitingforceexists,anditisthemainfactorforsurfaceandsubmergedhorizontalplatewhiletherollforcecanbeignored.3)Themaximumswaywaveexcitingforceexists,itisthemainfactorforsurfaceorsubmergedverticalplate,andtherollforceisabout20timesofhorizontalplate.

  • 标签: 板式 垂直 水下 波浪力 防波堤 散射
  • 简介:TheliftforcesonhorizontalcylindernearbottomisexperimentallyinvestigatdeatReynolds(Re)intherangelf2500~10000andKeulegan~CARPENTERNUMBERS(kc)intheintervalof5~20,andgapratio(e/D)isfrom(a0)areanalyzdebyusingtheFourieranalysesmethod.ItisfoundthatfoundthatbothCl&a0arethefunctionslftheKcnumber.

  • 标签: OSCILLATING flow horizontal cylinder LIFT forces
  • 简介:Thenumericalinvestigationofregularwavesinteractingwithasubmergedhorizontaltwin-platebreakwaterispresentedinthispaper.Anumericalmodelwithanabsorbingwave-makerisestablishedbasedontheVOFmethod.Thevalidityofthemodelisverifiedbyexperimentalresults.Comparisonsbetweenthenumericalandexperimentalresultsshowthatboththewatersurfaceprofilesandthewave-inducedpressurescanbemodeledaccurately.Wavedeformationoverthebreakwater,waterparticlevelocitiesaroundthebreakwater,andthewave-inducedpressuresonthestructurearenumericallyinvestigated.Thepressureamplitudesofthefundamentalandsecondharmonicsonthemodelsurfaceareexaminedinvariouswaterdepths.Thecomputedandexperimentalresultshaverevealedthatthehigherfrequencycomponentsaregeneratedattheonshoresideofthebreakwater.Furthermore,thecomputedresultsdemonstrateacirculatingflowformedattheonshoresideofthebreakwater.

  • 标签: 数值模拟 相互作用 防波堤 卧式 数学模型 验证实验
  • 简介:Centrifugeexperimentsarecarriedouttoinvestigatetheresponsesofsuctionbucketfoundationsunderhorizontaldynamicloading.Theeffectsofloadingamplitude,thesizeofthebucketandthestructuralweightonthedynamicresponsesareinvestigated.Itisshownthat,whentheloadingamplitudeisoveracriticalvalue,thesandattheupperpartaroundthebucketsoftensorevenliquefies.Theliquefactionindex(excessporepressuredividedbyinitialeffectivestress.Inthispaper,thedevelopmentaldegreeofexcessporepressureisdescribedbyliquefactionindex)decreasesfromtheupperparttothelowerpartofthesandfoundationintheverticaldirectionanddecreasesfromneartofarawayfromthebucket′ssidewallinthehorizontaldirection.Largesettlementsofthebucketandthesandaroundthebucketareinducedbythehorizontaldynamicloading.Thedynamicresponsesofthebucketofasmallerheight(whenthediameteristhesame)areheavier.Acycliccracksomedistancenearthebucketoccursinthesand.

  • 标签: 离心实验 抽水泵 水平动力载荷 海岸工程
  • 简介:重力的势能(GPE)变化由于horizontal/isopycnal旋涡散开和移流被检验。Horizontal/isopycnal旋涡散开概念上被分开成二步:激动人心并且subscale散开。与这二步联系的GPE变化被分析。另外,GPE变化由于激动人心并且在Eulerian坐标与horizontal/isopycnal移流联系的subscale散开被分析。这些公式为世界海洋被用于SODA数据。我们的分析显示在Eulerian坐标的horizontal/isopycnal移流能在模型介绍大人工的散开。在isopycnal坐标的GPE来源/水池仔细被连接到物理性质分发,这被显示出,例如温度,咸度和速度。与z协调比较,GPE来源/水池由于与isopycnal散开/移流联系的stirring/cabbeling是小得多的。尽管isopycnal坐标可以以处理侧面的散开是一种更好的选择,在传统的Eulerian坐标的移流术语能由于与移流联系的cabbeling生产GPE的人工的来源。减少如此的数字错误仍然是宏大挑战。

  • 标签: 涡流扩散 对流 能量学 等密度 z坐标