简介:Thispaperpresentsanimprovedunstructuredgridimmersedboundarymethod.Theadvantagesofbothimmersedboundarymethodandbodyfittedgridswhicharegeneratedbyunstructuredgridtechnologyareusedtoenhancethecomputationefficiencyoffluidstructureinteractionincomplexdomain.TheNavier-StokesequationwasdiscretizedspaciallywithcollocatedfinitevolumemethodandEulerimplicitmethodintimedomain.TherigidbodymotionwassimulatedbyimmersedboundarymethodinwhichthefluidandrigidbodyinterfaceinteractionwasdealtwithVOS(volumeofsolid)method.AnewVOScalculationmethodbasedongraphwaspresentedinwhichbothimmersedboundarypointsandcrosspointswerecollectedinarbitraryordertoformagraph.Themethodisverifiedwithflowpastoscillatingcylinder.
简介:Thescaleeffectleadstolargediscrepanciesbetweenthewakefieldsofmodel-scaleandactualships,andcausesdifferencesincavitationperformanceandexcitingforcestestsinpredictingtheperformanceofactualships.Therefore,whentestdatafromshipmodelsaredirectlyappliedtopredicttheperformanceofactualships,testresultsmustbesubjectedtoempiricalcorrections.Thisstudyproposesamethodforthereversedesignofthehullmodel.Comparedtoageometricallysimilarhullmodel,thewakefieldgeneratedbythemodifiedmodelisclosertothatofanactualship.Anon-geometricallysimilarmodelofaKoreanResearchInstituteofShipandOceanEngineering(KRISO)’scontainership(KCS)wasdesigned.Numericalsimulationswereperformedusingthismodel,anditsresultswerecomparedwithfull-scalecalculationresults.Thedeformationmethodofgettingthewakefieldoffull-scaleshipsbythenon-geometricallysimilarmodelisappliedtotheKCSsuccessfully.
简介:刚参加工作时,我在矿工会的主要工作之一就是为俱乐部放电影。上世纪80年代什么资源都紧张,遇到好片子几个影院串片轮流放映是常有的事,每次当我准备打出“跑片未到,敬请原谅”的幻灯片时,摩托车便伴随着发动机声呼啸而至,真是帮了大忙!
简介:在国内电动自行车市场上“咄咄逼人”的深圳科艾特电动车有限公司最近又有大动作了。