简介：-Theturbulencemechanismplaysanimportantpartinthemixingprocessandmomentumtransferofturbulence.Athree-dimensionalPrandtlmixinglengthtidalmodelhasbeendevelopedtosimulatetidalflowsandwaterquality.TheeddyviscositiesanddiffusivitiesarecomputedfromthePrandtlmixinglengthmodel.Inordertomodelthewaterqualityofanestuaryorcoastalareamanyinterdependentprocessesneedtobesimulated.Thesemaybeconvenientlyseparatedintothreemaingroups:transportandmixingprocesses,biochemicalinteractionofwaterqualityvariablesandtheutilizationandre-cyclingofnutrientsbylivingmatter.Themodelsimulatesfulloxygenandnutrientbalance,primaryproductivityandthetransport,reactionmechanismandfateofpollutantsovertidaltime-scales.ThemodelisappliedtonumericalsimulationoftidalflowsandwaterqualityinDalianBay.Themodelhasbeencalibratedagainstalimiteddatasetofhistoricalwaterqualityobservationsandingeneraldemonstra

简介：Inthisstudy,wesimulatedtyphoonwavesintheshallowwatersaroundtheZhoushanIslandsusingtheWaveWatch-III(WW3)modelversion5.16,thelatestversionreleasedbytheNationalOceanicandAtmosphericAdministration.Specifically,weusedin-situmeasurementstoevaluatetheperformanceofsevenpackagesofinput/dissipationsourcetermsintheWW3model.WeforcedtheWW3modelbywindfieldsderivedfromacombinationoftheparametricHollandmodelandhigh-resolutionEuropeanCenterforMedium-RangeWeatherForecasts(ECMWF)winddataina0.125°grid,hereincalledH-Ewinds.WetrainedtheH-EwindsbyfittingashapeparameterBtobuoy-measuredobservations,whichresultedinasmallestrootmeansquareerror(RMSE)of3ms?1forB,whentreatedasaconstant0.4.Then,weappliedtheseveninput/dissipationtermsofWW3,labelledST1,ST2,ST2+STAB2,ST3,ST3+STAB3,ST4,andST6,tosimulatethesignificantwaveheight(SWH)upto5mduringtyphoonsFungwongandChan-homaroundtheZhoushanIslands.WethencomparedtheSWHsofthesimulatedwaveswiththosemeasuredbythein-situbuoys.TheresultsindicatethatthesimulationusingST2performsbestwithanRMSEof0.79mfortyphoonFung-wongandanRMSEof1.12mfortyphoonChan-hom.Interestingly,wefoundthesimulatedSWHresultstoberelativelyhigherthanthoseoftheobservationsintheareabetweenHangzhouBayandtheZhoushanIslands.Thisbehaviorisworthyoffurtherinvestigationinthefuture.

简介：Principalstressaxesrotationinfluencesthestress-strainbehaviorofsandunderwaveloading.Aconstitutivemodelforsand,whichconsidersprincipalstressorientationandisbasedongeneralizedplasticitytheory,isproposed.Thenewmodel,whichemploysstressinvariantsandadiscretememoryfactorduringreloading,isoriginalbecauseitquantifiesmodelparametersusingexperimentaldata.Foursetsofhollowtorsionexperimentswereconductedtocalibratetheparametersandpredictthecapabilityoftheproposedmodel,whichdescribestheeffectsofprincipalstressorientationonthebehaviorofsand.Theresultsprovetheeffectivenessoftheproposedcalibrationmethod.

简介：two-time-level，三维的数字海洋发行量模型(命名MASNUM)与一个二水平的、单个步的Eulerian提交向后时差计划被建立。大规模海洋的运动的一个数学模型基于协调的地面追随者，Boussinesq，海洋动力学的平均Reynolds的原始方程。一个简单却很实际的Eulerian提交向后方法被采用为barotropic和baroclinic模式作为时差方法代替大多数比较喜欢的跳蛙游戏计划。提交向后方法具有精确性的秒顺序，由每时间步要求一仅仅功能评估计算地有效，并且没有在三水平的计划固有的计算模式。这个方法比跳蛙游戏计划优异因为稳定性的最大的时间步骤这样象在蹒跚的网孔的跳蛙游戏计划的一样两次大计算效率能被加倍。一个空间变光滑方法被介绍在数字集成控制非线性的不稳定性。模仿赤道的Rossbysoliton的繁殖的一个理想的数字实验被执行测试振幅和这个新模型的阶段错误。这个发行量模型的表演进一步被验证与一地区性(西北太平洋)并且一伪全球(有排除的北极海洋的全球海洋模拟)模拟实验。这二个数字实验与观察显示出相当好的同意。在这二个实验的稳定性的最大的时间步也在采用跳蛙游戏计划的这个模型和那个模型之间被调查并且比较。

简介：ItiswellknownthattheReynoldsnumberhasasignificanteffectonthevortex-inducedvibrations(VIV)ofcylinders.Inthispaper,anovelin-line(IL)andcross-flow(CF)couplingVIVpredictionmodelforcircularcylindershasbeenproposed,inwhichtheinfluenceoftheReynoldsnumberwascomprehensivelyconsidered.TheStrouhalnumberlinkedwiththevortexsheddingfrequencywascalculatedthroughafunctionoftheReynoldsnumber.ThecoefficientofthemeandragforcewasfittedasanewpiecewisefunctionoftheReynoldsnumber,anditsamplificationresultedfromtheCFVIVwasalsotakenintoaccount.TheoscillatingdragandliftforcesweremodelledwithclassicalvanderPolwakeoscillatorsandtheirempiricalparametersweredeterminedbasedonthelock-inboundariesandthepeak-amplitudeformulas.Anewpeak-amplitudeformulafortheILVIVwasdevelopedundertheresonanceconditionwithrespecttothemass-dampingratioandtheReynoldsnumber.Whencomparedwiththeresultsfromtheexperimentsandsomeotherpredictionmodels,thepresentmodelcouldgivegoodestimationsonthevibrationamplitudesandfrequenciesoftheVIVbothforelastically-mountedrigidandlongflexiblecylinders.ThepresentmodelconsideringtheinfluenceoftheReynoldsnumbercouldgenerallyprovidebetterresultsthanthatneglectingtheeffectoftheReynoldsnumber.

简介：ScaleeffectofISWsloadsonFloatingProductionStorageandOffloading(FPSO)isstudiedinthispaper.TheapplicationconditionsofKdV,eKdVandMCCISWstheoriesareusedinthenumericalmethod.ThedepthaveragedvelocitiesinducedbyISWsareusedforthevelocity-inletboundary.Threescalerationumericalmodelsλ=1,20and300wereselected,whichthescaleratioisthesizeratioofnumericalmodelstotheexperimentalmodel.Thecomparisonsbetweenthenumericalandformerexperimentalresultsareperformedtoverifythefeasibilityofnumericalmethod.Thecomparisonsbetweenthenumericalandsimplifiedtheoreticalresultsareperformedtodiscusstheapplicabilityofthesimplifiedtheoreticalmodelsummarizedfromtheloadexperiments.Firstly,thenumericalresultsofλ=1numericalmodelshowedagoodagreementwithformerexperimentalandsimplifiedtheoreticalresults.ItisfeasibletosimulatetheISWsloadsonFPSObythenumericalmethod.Secondly,thecomparisonsbetweentheresultsofthreescalerationumericalmodelsandexperimentalresultsindicatedthatthescaleratioshavemoresignificantinfluenceontheexperimentalhorizontalforcesthantheverticalforces.Thescaleeffectofhorizontalforcesmainlyresultsfromthedifferentviscosityeffectsassociatedwiththemodel’sdimension.Finally,throughthecomparisonsbetweenthenumericalandsimplifiedtheoreticalresultsforthreescaleratiomodels,thesimplifiedtheoreticalmodelofthepressuredifferenceandfrictionforcesexertedbyISWsonFPSOisappliedforlarge-scaleorfull-scaleFPSO.

简介：Asimplethree-dimensionaltidalmodelisusedtoexaminetheM2tidalcurrentdistributioninanortheasternpartoftheEastChinaSea,especiallytheverticalvariationofthecurrentintheregion.ComputedM2currentiscomparedwithobservationsavailableandfoundtobeingoodagreement.Mainfeaturesofthecalculatingmethodinthisstudyare:(1)Verticalvariationofthetidalcurrentistakenasafunetionofthedepth-meanvelocity:(2)themethodisapplicabletoavarietyoftheverticaleddyviscosities;(3)ithasafineverticalresolution,especiallyneartheseabootom.So,thismethodnotonlyenablesustogetasteadystatesolutioneasilybutalsodepictseffectsofthefrictionontheverticalvariationofthecurrentmuchbetter.

简介：Thegeophysicalmodelfunction(GMF)describestherelationshipbetweenbackscatteringandseasurfacewind,sothatwindvectorscanberetrievedfrombackscatteringmeasurement.TheGMFplaysanimportantroleinoceanwindvectorretrievals,itsperformancewilldirectlyinfluencetheaccuracyoftheretrievedwindvector.Neuralnetwork(NN)approachisusedtodevelopaunifiedGMFforC-bandandKu-band(NN-GMF).EmpiricalGMFCMOD4andQSCAT-1areusedtogeneratethesimulatedtrainingdata-set,andGaussiannoiseatasignalnoiseratioof30dBisaddedtothedata-settosimulatethenoiseinthebackscatteringmeasurement.TheNN-GMFemploysradiofrequencyasanadditionalparameter,soitcanbeappliedforbothC-bandandKu-band.Analysesshowthattheσ0predictedbytheNN-GMFiscomparablewiththeσ0predictedbyCMOD4andQSCAT-1.AlsothewindvectorsretrievedfromtheNN-GMFandempiricalGMFCMOD4andQSCAT-1arecomparable,indicatingthattheNN-GMFisaseffectiveastheempiricalGMF,andhastheadvantagesoftheuniversalform.

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简介：Environmentalloadistheprimaryfactorinthedesignofoffshoreengineeringstructuresandoceancurrentistheprincipalenvironmentalloadthatcausesunderwaterstructuralfailure.Incomputationalanalysis,thecalculationofcurrentloadismainlybasedonthecurrentprofile.Thecurrentprofilemodel,whichisbasedonastructuralfailurecriterion,isconducivetodecreasingtheuncertaintyofthecurrentload.Inthisstudy,weusedprototypemonitoringdataandtheempiricalorthogonalfunction(EOF)methodtoinvestigatethecurrentprofileintheSouthChinaSeaanditscorrelationwiththedesignofunderwaterstructuralstrengthandthedynamicdesignoffatigue.Theunderwaterstructuralstrengthdesigntakesintoaccountthesizeofthestructureandtheservicewaterdepth.Weproposeprofilesfortheoverallandlocaldesignsusingtheinversefirst-orderreliabilitymethod(IFORM).Weextractedthecharacteristicprofilecurrent(CPC)ofthemonitoredseaareatosolvedynamicdesignproblemssuchasvortex-inducedvibration(VIV).WeusedrandomsamplingtoverifythefeasibilityofusingtheEOFmethodtocalculatetheCPCfromthecurrentdataandidentifiedthemainproblemsassociatedwithusingtheCPC,whichdeservecloseattentioninVIVdesign.Ourresearchconclusionsprovidedirectreferencesfordeterminingcurrentloadinthisseaarea.Thisanalysismethodcanalsobeusedintheanalysisofotherseaareasorfieldvariables.

简介：通常一个维(1-D)实验咸度侵入模型被限制到自然冲积河口。然而，这研究试图调查它的能力在马来西亚为Terengganu河的一个掩盖的冲积河口建模。在河的嘴的构造防波提从公海的直接影响掩盖河口。沿着河口的咸度密度被收集在期间湿并且为在构造防波提前后的情形的旱季。而且，淡水分泌物，潮汐的举起和深测术数据也作为模型输入被测量。一好合适在模仿并且观察的变量之间被表明，也就是为两种情形的咸度分发和侵入长度。因此，结果显示出那1-D实验咸度模型能在Terengganu河口为掩盖的河口状况被利用，但是与一个起始的点的一颗适当决心。而且，在学习区域的咸度侵入大部分依赖于淡水分泌物而非潮汐的举起变化，这被观察。在学习区域的咸度侵入长度的规模与the-1/2力量的河分泌物成正比。实验咸度模型和分泌物驱动的1-D的二根线基于适合很好到对方的方程，这被显得，与150的平均预言的最小的淡水分泌物，m3/s将被要求在水吸入车站附近在高水位线呆滞(HWS)期间维持可接受的咸度层次，它从河嘴在10.63km被定位。

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：AWRF-Chemmodelincludingacomprehensivegas-phasenitrogenchemistrymodulewasusedtosimulateaseveredusteventappearingintheeasternChinaon19-25March,2002.ThemodelingresultwellreproducedPM10concentrationsinvariousdistancesfromthedustsourcesandthetransportpathwayoftheduststrom.TheresultsshowedthatboththeconcentrationsandthedrydepositionfluxesofPM10increasedovertheChinaseasduringthedusteventfollowingthepassageofacoldfrontsystem.ThemaximumfluxesofPM10intheYellowSeaandtheEastChinaSeaduringthedusteventwere5.5and8.4timesofthosebeforetheevent,respectively.However,thetemporalvariationsofthedrydepositionfluxesofparticulateinorganicnitrogendifferedovertheYellowSeafromthoseovertheEastChinaSea.NitrateandammoniuminthewholenorthernChinarapidlydecreasedbecauseoftheintrusionofdust-loadedairon19March.ThedustplumearrivedintheYellowSeaon20March,decreasingtheparticulateinorganicnitrogeninmassconcentrationaccordingly.TheminimumdrydepositionfluxesofnitrateandammoniumintheYellowSeawereabout3/5and1/6ofthosebeforethedustarrival,respectively.Incontrast,whenthedustplumecrossedovertheYangtzeDeltaarea,itbecameabundantinnitrateandammoniumandincreasedtheconcentrationsanddrydepositionfluxesofparticulateinorganicnitrogenovertheEastChinaSea,wherethemaximumdrydepositionfluxesofnitrateandammoniumincreasedapproximatelyby4.1and2.6timesofthosepriortothedustarrival.