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ID:23528061
大小:1.48 MB
页数:62页
时间:2018-11-08
《考虑流固耦合时海底管道悬跨段非线性动力分析》由会员上传分享,免费在线阅读,更多相关内容在学术论文-天天文库。
1、考虑流固耦合时的海底管道悬跨段非线性动力分析摘要本文以海底管线的涡激振动为研究对象,介绍了管跨段的形成原因,阐述了涡激振动的产生机理、特点。本文进行了海底管线管跨段的物理模型试验,针对不同的管跨长度,管内有无内流流动,波、流共同作用等不同的工况,进行了管跨段动力响应研究。通过对多组实验数据的分析,得出:管内流体作用将对管跨段振动频率产生一定影响;海流涡激作用下,管跨段横向振动响应幅值要大于顺向相应幅值,但有波浪作用伴随时此种情况有时会改变;管跨长度的变化对管线响应影响较大,跨长应尽力避开使管线出现共振的长度。在分析实验结果的基础上,提出了考虑流固耦合时非线性
2、的涡激升力表达式,建立了考虑流固耦合时海底管线的动力方程及其时程分析方法。以实验管道模型为算例,用有限元方法计算了考虑流固耦合与未考虑流固耦合时管道的动力响应,并比较了两者的差异。算例表明:在外流场流速较大的条件下,不考虑流固耦合时的计算结果明显小于考虑流固祸合时的计算结果,因此,偏于不安全。分析认为,在极端海况条件下,考虑流固耦合的分析方法更符合实际情况。关键词:涡激升力流固耦合海底管道非线性动力分析实验研究NonlinearDynamicAnalysisonFreeSpanSubmarinePipelinesConsideringFluid-Struct
3、ureInteractionAbstractThispapermainlyfocusesontheVortex—InducedVibration(VIV.)ofsubmarinepipeline.Thereasonofcausingafreespantosubmarinepipelineisdescribed.Thegeneratingmechanism,aswellaspropertiesofVIVareexpressed.Aphysicalmodelexperimentoffreespansubmarinepipelineiscarriedout.Dyn
4、amicresponseoffreespanconveyinginternalflowofdifferentlength,isinvestigatedunderdifferentwaveheights,currentvelocitymadtheircombinations.Viaanalyzingofexperimentaldata;someconclusionsareobtained:Thecross—flowresonantamplitudeislargerthanin—lineresonantamplitudewhenthevortexshedding
5、inducedbyoceancurrentappears,buttheparticipationofwaveswillchangethisphenomenonsometimes.Theresponseofafreespanpipelineisaffectedmuchbyitslength,sothespanlengthmustbekeptawayfromthelengthwhichcancauseresonanceofpipeline.ExpressionofnonlinearliftforcesforVIV,consideringfluid—structu
6、reinteraction,isputforwardviaanalyzingtheexperimentalresults.Nonlineardynamicequation,consideringfluid·structureinteraction,ofpipelineisputforward.Takingexperimentalmodelofpipeline,谢tIlandwithoutfluid-structureinteraction,iscomputedandcomparedbyusingtheFiniteElementmethod.Theanalys
7、isshowsthattheresponseofpipelineunconsideringfluid—structureinteractionisobviouslylessthanthatofpipelineconsideringfluid—structureinteraction.Theanalysisshowsthatmethodconsideringfluid—strucRtreinteractionismorereasonableunderhighexternalsteadyvelocity.Keywords:liftforcesforvortex-
8、inducedvibration;fluid—str
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