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500 个结果
  • 简介:与哈尔滨Devi自动化设备发展公司合作的Daqing石油化学的同伴的号码2化学植物,有限公司在butanol/octanol单位的含氧合成的反应堆采用了没有模型的控制系统完全在一次尝试在反应堆解决对CO集中的稳定的控制的问题在与反应化工物品的关系在含氧合成的反应堆优化反应条件,导致反应尾巴气体的分泌物和丙烯的减少的单位消费的重要减小。

  • 标签: 丁醇 辛醇 大庆石化公司 企业管理
  • 简介:AtestrigisbuilttomodelthedynamicresponseofsubmarinepipelineswithanunderwatershakingtableintheStateKeyLaboratoryofCoastalandOffshoreEngineering,DalianUniversityofTechnology,China.Modeltestsarecarriedouttoconsidertheeffectsofexcitingwavedirectionsandtypes.Basedontheexperimentalresults,twohydrodynamicforcemodelsderivedfromMorisonequationandWakemodelarepresentedrespectively.Byuseofhydrodynamicforcemodelssuitableforfreespanningsubmarinepipelinesunderearthquakes,discretizedequationsofmotionareobtainedandfiniteelementmodelsareestablishedtoanalyzedynamicresponseoffreespanningsubmarinepipelinesubjectedtomulti-supportseismicexcitations.ThecomparisonofnumericalresultswithexperimentalresultsshowsthattheimprovedMorisonandWakehydrodynamicforcemodelscouldsatisfactorilypredictdynamicresponseonthefreespanningsubmarinepipelinessubjectedtoearthquakes.

  • 标签: 水动力模型 底悬跨管道 海底管道 地震作用 模型试验 国家重点实验室
  • 简介:Ahigher-efficientthree-dimensionalnon-hydrostaticmodelisdevelopedtosimulatesmallamplitudefreesurfaceflowsbasedonastaggeredunstructuredgrid.Inthismodel,afractionalstepalgorithmisadoptedtosolvetheNavier-Stokesequationsintwomajorsteps.Atop-layerpressuremethodisproposedtominimizethenumberofverticallayersandsubsequentlythecomputationalcost.Threeclassicalexamplesofsmallamplitudefreesurfaceflowsareusedtodemonstratethecapabilityandefficiencyofthemodel.Thesatisfactoryresultsdemonstratedthecapabilityandefficiencyofmodellingarangeofsmallamplitudefreesurfaceflowswithonlyasmallnumberofverticallayers.

  • 标签: higher-efficient NON-HYDROSTATIC small AMPLITUDE free surface
  • 简介:Theproblemofconstructingamodelreferenceadaptivecontrollawforanuncertain1-dimensionalparabolicsystemisconsideredinthisarticle.Thecontrollerdesignedhereinvolvesonlytheplantstatebutnoitsderivatives.Aprioriboundsontheplant'suncertainparametersareusedtoproposeswitchinglawswhichserveasanadaptivemechanism.Theexponentialdecaytozeroofthestateerrorwithanyprescribedrateisguaranteedbychoosingacontrollerparametercorrespondingly.Numericalstudiesarealsopresentedtoillustratetheapplicabilityofthecontrollaw.

  • 标签: 模型参考自适应控制 抛物型系统 变结构 自适应控制律 控制器参数 导数
  • 简介:Thethree-dimensionalNavier-Stokesequationsweresolvedwiththefractionalstepmethodwherethehydrostaticpressurecomponentwasdeterminedfirst,whilethenon-hydrostaticcomponentofthepressurewascomputedfromthepressurePoissonequationinwhichthecoefficientmatrixispositivedefiniteandsymmetric.Theeddyviscositywascalculatedfromtheefficientk-εturbulencemodel.TheresultingmodeliscomputationallyefficientandunrestrictedtotheCFLcondition.Computationswithandwithouthydrostaticapproximationwerecomparedforthesamecasestotestthevalidityoftheconventionalhydrostaticpressureassumption.Themodelwasverifiedagainstanalyticalsolutionsandexperimentaldata,withexcellentagreement.

  • 标签: 网栅 流体静力学 湍流 自由表面流
  • 简介:一个改进方法被建议模仿骚乱介绍的焕发,基于有限Markov州的模型。作为到文学的一个对比,一致地分布式的变量发生在某个状态期间,它比传统的Markov模型与更少状态贡献紧张变化的相等的模拟。它的也发现有20个状态的建议Markov模型在汽车协变性分析提供令人满意的近似给试验性的结果。而且,停止概率和吝啬的褪色时间是比有相等的状态的传统的Markov模型的那些更精确的。

  • 标签: 马尔可夫模型 状态模型 自由空间 光链路 仿真 城市
  • 简介:Asemi-implicit3-Dnumericalformulationforsolvingnon-hydrostaticpressurefree-surfaceflowsonanunstructured,sigmagridisproposed.Pressure-splittingand9semi-implicitmethodsareinheritedandreformedfromCasulli'sz-coordinateformulation.Thenon-orthogonalsigma-coordinatetransformationleadstoadditionalterms.Theresultinglinearsystemforthenon-hydrostaticcorrectionisdiagonallydominantbutunsymmetric,anditissolvedbytheBiCGstabmethod.Incontrastwithz-coordinatenon-hydrostaticmodels,thenewmodelfitsverticalboundariesmuchbetter,whichisimportantforthelong-timesimulationofsedimenttransportandriverbeddeformation.Alock-exchangedensityflowiscomputedtodeterminewhetherthenewschemeisabletosimulatenon-hydrostaticfree-surfaceflows.ThenewmodelisfurtherverifiedusingthefielddataofanaturalriverbendofthelowerYangtzeRiver.Goodagreementbetweensimulationsandearlierresearchresults,fielddataisobtained,indicatingthatthenewmodelisapplicabletohydraulicprojectsinrealrivers.

  • 标签: 三维数值模型 自由表面流动 静水压力 非结构化 半隐式 电网
  • 简介:A3-DnumericalformulationisproposedonthehorizontalCartesian,verticalsigma-coordinategridformodelingnon-hydrostaticpressurefree-surfaceflows.Thepressuredecompositiontechniqueandθsemi-implicitmethodareused,withthesolutionprocedurebeingsplitintotwosteps.First,withtheimplicitpartsofnon-hydrostaticpressuresexcluded,theprovisionalvelocityfieldandfreesurfaceareobtainedbysolvinga2-DPoissonequation.Second,thetheoryofthedifferentialoperatorisemployedtoderivethe3-DPoissonequationfornon-hydrostaticpressures,whichissolvedtoobtainthenon-hydrostaticpressuresandtoupdatetheprovisionalvelocityfield.Whenthenon-orthogonalsigma-coordinatetransformationisintroduced,additionaltermscomeintobeing,resultingina15-diagonal,diagonallydominantbutunsymmetriclinearsysteminthe3-DPoissonequationfornon-hydrostaticpressures.TheBiconjugateGradientStabilized(BiCGstab)methodisusedtosolvetheresulting3-Dunsymmetriclinearsysteminsteadoftheconjugategradientmethod,whichcanonlybeusedforsymmetric,positive-definitelinearsystems.Threetestcasesareusedforvalidations.Thesuccessfulsimulationsofthesmall-amplitudewave,asupercriticalflowoverarampandaturbulentflowintheopenchannelindicatethatthenewmodelcansimulatewellnon-hydrostaticflows,supercriticalflowsandturbulentflows.

  • 标签: 三维数值模型 自由表面流 静水压力 坐标变换 半隐式 非对称线性系统
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