海底管道周圍局部沖刷數值模擬研究.pdf

1、大連理工大學碩士學位論文海底管道周圍局部沖刷數值模擬研究姓名：孫建偉申請學位級別：碩士專業(yè)：港口、海岸及近海工程指導教師：孫昭晨20091218海底管道周同局部沖刷數值模擬研究TheStlJdyofNumericalModelForLocalUnderO仃shorePipelinesAbstractThelocaJscourbelowo行shorepipeliIlesisiIlducedbytllelongte加ederosionofc

2、肼ems鋤IdwaVesThefbespaIlpropagatesalongt11epipeliIlea11dinducesstnJcturalandfati擘mef撕lureofpipeliIlesA仃emerldouseconomicloss鋤deIⅣiromentaldisaster、)l，iUoccur，oncethepipelinef撕lsso，itisiIIlpport觚ttoforec嬲ttllescourdeepbelo

3、wpipelineAvenical似odimensioIlal(2D)n啪ericalmodelisdevelopedThecomrolIingequationsaretlleReynoldsaveragedNSequationswitllthestall∈brd尼一sn曲ulenceclosu】reAnappropriatewml劬ctionisselectedtocaJculatet11eveloci諺neartllebedTheg

4、oVemingeq崛tionsaresolVedbyuSingfinitedifferencemetllodiIlageneralcuⅣilinearcoordinatesvstemTwekindsofsedimentscohesivesandandnoncohesivesandhavebeeniIlvestigatedfortheirⅡlresholdVeloci夠a11dsettlingvelocit)，Botllsuspended

5、loadaIldbedloadareconsideredinthescourmodelA胡terablemeshtecllrliqueisappliedtomedelthechallgeofbedleVelonmeprocessofscourSimultalleity，Atimemarcmngschemea11dasarldslideschemeareproposedforthescourcalculationt0miIlishn啪er

6、ationt婦eandinsuren啪ericalstabili刎ionThemodelisvalidatedaIldtheagreementbe帆eent11esimulatedresultsandtheexperimentda_tashowsthepresentscourmodelisabletopredicttheequilibri啪profileAtlast，OllSetofscourissimulated鋤dgetmeonse

7、tofscourtlleory(衲upsofscoureXperimentweretookaIldtheprocessofscour、ⅣasanalysedFinally，aemDiricalfomlulaaboutscourdeepw骶concludedOnthebaseofsinglecunemmodel，modelsof、)I，a，Veandcombinedwavesandcun’entsaredevelopedThemodelo

8、fwaveissimulatedbyuseofoscillatingnowatt11eboLuldalysofconlpmationaldomainThemodelofcombinedwavesaIldcurrentissimulatedbylIseofcu】nnentmodel踟1dafhxationoffirstorderlinear、Ⅳavet11eorySuspendedandbedloadareconsideredi11tll

9、escourmodelAtime—marcllingmetllodsuitableformodelingwave—inducedscol】risappliedintllisstudytoaccommoda傖differenttimescalesofmenow鋤dmofpholo西c鰣cl幽gesTheseabedmorphologycalculationisb嬲ed伽theperiodaVeragedsedimenttransportr