简介:Forstudyingthedynamicperformanceofsubseaumbilicalcablelayingsystemandachievingthegoalofcabletensionandlayingspeedcontrol,therigidfiniteelementmethodisusedtodiscreteandtransformthesystemintoarigid-flexiblecouplingmulti-bodysystemwhichconsistsofrigidelementsandspring-dampingelements.ThemathematicalmodelofsubseaumbilicalcablelayingsystemkinematicchainispresentedwiththesecondorderLagrangeequationinthejointcoordinatesystem,anddynamicmodelingandsimulationisperformedwithADAMS.Thedynamicanalysisisconductedassumingthefollowingthreestatuses:ideallaying,practicallayingunderwavedisturbance,andpracticallayingwithtensioncompensation.Resultsshowthatmotiondisturbancesofthelayingbudgeunderseawaves,especiallywithheavingandpitching,willcauserelativelyseriousfluctuationsincabletensionandlayingspeed.Tensioncompensation,i.e.,activebacktensiontorquecontrolcanrestrictcontinuoustensionincreasingordecreasingeffectivelyandrapidly,thusavoidingcablebreachorbuckling.
简介:Smoothedparticlehydrodynamics(SPH)isaLagrangianmeshlessparticlemethod.Itisoneofthebestmethodforsimulatingviolentfreesurfaceflowsinfluidsandsolvinglargefluiddeformations.Dambreakingisatypicalexampleoftheseproblems.ThebasisofSPHwasreviewed,includingsometechniquesforgoverningequationresolution,suchasthesteppingmethodandtheboundaryhandlingmethod.Thennumericalresultsofadambreakingsimulationwerediscussed,andthebenefitsofconceptslikeartificialviscosityandpositioncorrectionwereanalyzedindetail.Whencomparedwithdambreakingsimulatedbythevolumeoffluid(VOF)method,thewaveprofilegeneratedbySPHhadgoodagreement,butthepressurehadonlyreasonableagreement.Improvingpressureresultsisclearlyanimportantnextstepforresearch.
简介:<正>19–24October2014SingaporeCONFERENCETHEMESTheoverallaimoftheICHDConferenceistoprovideaforumforparticipantsfromaroundtheworldtoreview,discussandpresentthelatestdevelopmentsinthebroaddisciplineofhydrodynamicsandfluidmechanics.ThefirstInternationalConferenceonHydrodynamics(ICHD)wasinitiatedin1994inWuxi,China.Sincethen,9moreICHDconferenceswereheldsubsequentlyinHongKong,Seoul,Yokohama,Tainan,Perth,Ischia,Nantes,ShanghaiandStPetersburg.EvidentlytheICHDconferencehasbecomeanimportanteventamongacademics,
简介:通过CFD(计算流体力学)方法对船舶领域两个典型的工程实例进行了数值计算和流场模拟,模拟的流场与船池试验的流场很吻合。数值计算结果和试验值比较,在特定n范围内相对误差在6.6%以内,满足工程要求。表明数值方法在船舶航速预报方面具有一定的工程实用性,以CFD计算结果为依据光顺流场流线优化船舶阻力性能的可行性也得到工程实例证明。