简介:ThispaperpresentstheresearchontheexternalmechanismofcollisioncharactersforaSPARplatform.ThecollisioncharactersofSPARplatformhavenotattractedsomuchattentionasthatofshipsinthepast,becauseshortofthiskindofcollisionaccidentsreported.ButwiththeincreasingnumberofSPARplatformsintheworld,thepossibilityofsuchkindofaccidentalsoincreases.Therefore,itisnecessarytomasterthecharacterofSPARcollision.Modeltesttechniqueisemployedtostudytheexternalmechanism.ThecollisionscenarioisashipcollidingwithaSPARplatformmooredinthesitewith1500meterswaterdepth.ThestrikingshiphitstheSPARplatformonthehardtanknearwatersurfaceinitslongitudinaldirection.ThespecificsoftheSPAR'smotionsandthetensionforcesofthemooringlinesarecollectedtosummarizethehydrodynamiccharactersinthecollisionscenario.ItisfoundthatthemaximaldisplacementsandthemaximalpitchanglesoftheSPARplatform,andthemaximaltensionforcesofmooringlinesarealllinearlyproportionaltotheinitialvelocityofthestrikingshipbasically.Mooringlinesplayelasticrolesinthecollisioncourse.
简介:精确预言近海结构运动反应和伙伴绳索线紧张在技术应用和科学研究是重要的。在我们的学习,一个truss圆材平台,在墨西哥湾操作了,被一对内部地数字的代码夫妇数字地模仿并且分析。站台运动回答和联系绳索行紧张通过一个时间领域被计算并且调查非线性的联合动态分析。在模拟和相应领域大小之间的令人满意的同意在联系的将军,显示数字代码能被用来进行与它的绳索和起床人系统交往的truss圆材的时间域分析。基于在线性、非线性的结果之间的比较,在预言站台运动反应和绳索行紧张的非线性的相对重要性被估计并且介绍。通过联合并且伪静电干扰分析,在在预言系在的行紧张和站台运动的站台壳和绳索/起床人的系统之间的动态联合效果的重要性被确定。这些结果可以提供从属便于大规模的数字模拟和设计的必要信息近海结构。
简介:Tosolvethedimensionallimitationsofphysicalmodelsintests,anequivalentwaterdepthtruncateddesignforaclassicalSPARworkingin913mwaterwasinvestigated.Thewaterdepthwasreducedto736mandthento552m.Asthiswasdone,themooringlinelengths,EAvalue,andmasspermeterwereadjusted.Truncationrulesandformulasforparametersandtruncationfactorswereproposed.SPARstaticcharacteristicsweremadetobeconsistentwiththoseatfullwaterdepth.Thenfurthertime-domaincoupledanalysiswascarriedoutfortheSPARwhenthemooringsystemexperiencedwaves.Themooringlinesweresimulatedbyquasi-staticmethod.Globalresponsesandmooringlineforceswerefoundtoagreewellwithtestresultsforaprototypeatthatwaterdepth.Thetruncationmethodprovedtoberobustandreliable.
简介:Theresearchpurposeofthispaperistoestimatetheimpactsoftheparametersoftheguideplateontheverticalmotioncharacteristicsofthemoonpoolfluid.Withthevolumeoffluid(VOF)method,three-dimensionalmodelsofthemoonpoolfluidmotionsofthetrusssparplatformareestablished.Simulationresultsarethenpresentedforthemoonpoolforcedoscillationbyemployingthedynamicmeshmethodanduser-definedfunctionsinFLUENT.Themotionsofthemoonpoolfluidandtheloadsontheguideplatesareobtainedforbothcasesofsquare-ringandcrisscross.Theresultsshowthattheshapeandareaoftheguideplateatthebottomofthemoonpoolhaveasignificantimpactonthephysicalparametersofthemoonpool,includingtheloadonthemoonpoolguideplate,motionformofthemoonpoolfluidandthemassflowrate.
简介:华南海在深海的区域包含巨大的油和煤气的资源。然而,为深海的探索的钥匙之一,深海的漂浮平台的调查,是很不适当的。在这份报纸,作者在华南海环境学习了并且比较水动力学和典型深海的平台的全球运动行为。水动力学漂浮的平台的三种主要类型当模特儿,例如半能沉入水中,紧张腿站台(TLP),并且捆绑海岸警卫队女子后备队队员,它能潜在地在华南海被利用,被使用3-D潜力理论建立。另外,显著地影响水动力学的一些重要考虑被给。在及时,在在100-y,10-y,和1-y的变化时间的风,随机的波浪,和电流下面的领域归还时期环境条件的频率领域以及全球运动的RAO被预言,比较,并且分析。结果显示举和TLP的特别沥青运动是有利的。当随机的波浪的高峰时期是低的时,Truss海岸警卫队女子后备队队员的举反应与TLP的完美、可比较。然而,沥青运动捆绑海岸警卫队女子后备队队员比的非常地大半能沉入水中并且TLP。
简介:Thecoupledhull,mooringandriseranalysistechniquesintimedomainarewidelyrecognizedastheuniqueapproachtopredicttheaccurateglobalmotions.However,thesecomplexissueshavenotbeenperfectlysolvedduetoalargenumberofnonlinearfactors,e.g.forcesnonlinearity,mooringnonlinearity,motionnonlinearityandsoon.Thispaperinvestigatesthecoupledeffectsthroughthenumericaluncoupledmodel,mooringcoupledmodelandfullycoupledmodelaccountingmooringandrisersbasedonanoveldeepdraftmulti-sparwhichisespeciallydesignedfordeepwaterin2009.Thenumericalstatic-offset,free-decay,wind-actiontestsareexecuted,andfinallythreehourssimulationsareconductedunder100-yearreturnperiodofGOMconditionsinvolvingwave,windandcurrentactions.Thedampingcontributions,responsecharacteristicsandmooringlinetensionsareemphaticallystudied.
简介:Wepresentastudyofthenonlinearcouplinginternalresonancefortheheaverollandpitchperformanceofasparplatformunderthewaveandvortex-inducedloadswhentheratioofthefrequenciesofheave,rollandpitchareapproximately2:1:1.Inconsiderationofvaryingwetsurface,thethreeDOFsnonlinearcoupledequationsareestablishedforthesparplatformundertheeffectofthefirst-orderwaveloadsintheheaveandpitch,andvortexinducedloadsintheroll.Byutilizingthemethodofmulti-scaleswhenthevortex-inducedfrequencyisclosetothenaturalrollfrequency,thefirst-orderperturbationsolutionisobtainedanalyticallyandfurthervalidatedbythenumericalintegration.Sensitivityanalysisisperformedtounderstandtheinfluenceofthedampingandtheinternaldetuningparameter.Twocaseswithinternalresonanceareshown.Thefirstcaseisthatnosaturationphenomenonexistsundersmallvortex-inducedloads.Thefirstorderperturbationsolutionillustratesthatonlythevortex-inducedfrequencymotioninrollandthesuper-harmonicfrequencymotioninheaveareexcited.Thesecondcaseisthatthevortex-inducedloadsarelargeenoughtoexcitethepitchandasaturationphenomenonintheheavemodefollows.Theresultsshowthatthereisnosteadyresponseoccurrenceforsomecases.Forthesecaseschaosoccursandlargeamplitudesresponsecanbeinducedbythevortex-inducedexcitation.