学科分类
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2 个结果
  • 简介:Athree-dimensional(3-D)oceanmodeliscoupledwithatwo-dimensional(2-D)seaicemodel,torevisitanonlinearadvectionmechanism,oneofthemostimportantmesoscaleeddygenesismechanismsinthemarginalicezone.Two-dimensionaloceanmodelsimulationssuggestnonlinearadvectionmechanismismoreimportantwhenthewatergetsshallower.Insteadofconsideringtheoceanasbarotropicfluidinthe2-Doceanmodel,the3-Doceanmodelallowstheseaicetoaffectthecurrentdirectlyinthesurfacelayerviaocean-iceinteraction.Itisfoundthatbothmesoscaleeddyandseasurfaceelevationaresensitivetochangesinawaterdepthinthe3-Dsimulations.Theverticalprofileofacurrentvelocityin3-Dexperimentssuggeststhatwhenthewaterdepthgetsshallower,thecurrentmovefasterineachlayer,whichmakestheseasurfaceelevationbenearlyinverseproportionaltothewaterdepthwiththesamewindforcingduringthesametime.Itisalsofoundthatbecauseoftheverticalmotion,themagnitudeofvariationsintheseasurfaceelevationinthe3-Dsimulationsisverysmall,beingonly1%ofthechangeinthe2-Dsimulations.Anditseemstheverticalmotiontobetheessentialreasonforthedifferencesbetweenthe3-Dand2-Dexperiments.

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  • 简介:Inordertotheoreticallystudythebucklepropagationofsubseapipelineswithslip-onbucklearrestors,atwo-dimensionalringmodelwassetuptorepresentthepipelineandanonlinearspringmodelwasadoptedtosimulatethecontactbetweenpipeline’sinnerwallsandbetweenpipeline’souterwallandslip-onbucklearrestor’sinnerwallduringbucklepropagation.Inaddition,somereversespringsareaddedtopreventthewallofleftandrightsidesseparatingfromtheinnerwallofslip-onbucklearrestors.Consideringlargedeformationkinematicsrelationsandtheelastic-plasticconstitutiverelationofmaterial,balanceequationswereestablishedwiththeprincipleofvirtualwork.Thevariationofexternalpressurewithrespecttothecross-sectionalareaofpipelineswasanalyzed,andthelowerboundofthecrossoverpressureofslip-onbucklearrestorswascalculatedbasedonMaxwell’senergybalancemethod.Bycomparingthetheoreticalresultswithexperimentandfiniteelementnumericalsimulation,thetheoreticalmethodisprovedtobecorrectandreliable.

  • 标签: subsea pipeline BUCKLE propagation NONLINEAR CONTACT