简介:Sloshingphenomenonintheliquidcargocarriershascaughttheattentionofresearchersastheinteractionbetweenthesloshingwavesandstructureisoneofthekeypointanddifficultyinthestudyofsloshing.Inthispaper,wecapturedthefreesurfacewithavolumeoffluid(VOF)methodandthencalculatedthemotionsandresponsesofthestructurebyadoptingtheReynolds-averagedNavier-Stokes(RANS)equationsforthewholefluiddomain.Withtheuseofuserdefinedfunctions(UDF)inFluent,theinteractionbetweenfluidandstructurewasthensimulated.Asareasonablesimplification,theauthorsstudiedtheresponseofasinglecantileverinatankundersloshingloads;Furtherstudyshouldpaymoreattentiontothemechanismsofinteractionbetweensloshingwavesandelasticstructures.
简介:安全生产永远是石油石化企业的基础和工作前提,要认真研究解决新情况新问题,2001年是深化改革之年,规范管理之年,降本增效之年,要实现2001年和各项工作任务和四大奋半目标,必须首先抓好安全生产,目前,集团公司的改革远未到位,机制转换还没有完成,工作千头万绪,怎么办?我认为,安全生产是一切工作的基础,是保证,沉有安全生产,我们就没和精力深化改革,规范管理,提高效益,2000年集团公司的火灾爆炸事故增多,其中“三纬”和管理责任造成的事故所占比例很大,几次安全检查特别是年底安全大检查,都发现了一些严重违章问题,如作业票和火票制度在很多企业得不到认真落实,禁烟制度执行不力,这都是严重事故隐患,如不立即纠正整改,将会酿成大祸,影响和贻误集团公司和股份公司的大局,对此,我们一定要有深刻的认识和高度的警觉。
简介:文章阐明了PBL教学法在“船舶强度与结构设计”课程教学中的应用,介绍了其具体实施步骤。实施效果显示,该方法取得了良好的教学效果,具有一定的参考意义。
简介:Thispaperpresentsanimprovedunstructuredgridimmersedboundarymethod.Theadvantagesofbothimmersedboundarymethodandbodyfittedgridswhicharegeneratedbyunstructuredgridtechnologyareusedtoenhancethecomputationefficiencyoffluidstructureinteractionincomplexdomain.TheNavier-StokesequationwasdiscretizedspaciallywithcollocatedfinitevolumemethodandEulerimplicitmethodintimedomain.TherigidbodymotionwassimulatedbyimmersedboundarymethodinwhichthefluidandrigidbodyinterfaceinteractionwasdealtwithVOS(volumeofsolid)method.AnewVOScalculationmethodbasedongraphwaspresentedinwhichbothimmersedboundarypointsandcrosspointswerecollectedinarbitraryordertoformagraph.Themethodisverifiedwithflowpastoscillatingcylinder.
简介:Ananalyticalstudywaspresentedonactivecontrolofsoundtransmissionintoavibro-acousticenclosurecomprisingtwoflexibleplates.Twotypesofactuatorswereused,i.e.acousticactuatoranddistributedleadzirconatetitanatepiezoelectric(PZT)actuatorinsteadofpointforceactuator.Usingthemodalacoustictransferimpedance-mobilitymatrices,theexcitationandinteractioninthecoupledsoundtransmissionsystemcanbedescribedwithclearphysicalsignificance.Withthecontrolsystemdesignedtogloballyreducethesoundfield,differentcontrolsystemconfigurationswereconsidered,includingthestructuralactuatorontheincidentplate,actuatoronthereceivingplate,acousticactuatoronthecavity,andtheircombinations.Theeffectivenessandperformanceofthecontrolstrategycorrespondingtoeachsystemconfigurationwerecomparedanddiscussed.Theroleandcontrolmechanismofeachtypeofactuatorwereofparticularinterest.Itwasshownthattheincidentplateactuatoriseffectiveincontrollingthecavity-dominatedmodesandthestructuralmodesdominatedbytheincidentplateandreceivingplate.Twomaincontrolmechanismsareinvolvedinthiscontrolconfiguration,i.e.,modalsuppressingandmodalrearrangement.Forcontrolsystemconfigurationwithonlyacousticactuatorintheenclosure,themechanisminvolvedinthisarrangementispurelymodalsuppression.Desirableplacementsofstructuralactuatorsintermsoftotalpotentialenergyreductionwerealsodiscussed.