学科分类
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12 个结果
  • 简介:WithrespecttothecrestspillwaywithlargeunitdischargeandlowFroudenumber,thehydraulicsoftheslit-typeenergydissipaterattheoutletshouldbenoticedduetothecomplicatedflowregimes.Inthepresentpaper,someissuesabouthydrauliccharacteristicswereexperimentallyinvestigatedbymeansoffiveslit-typeoutletsandfourtetrahedrons,includingtheflowchoking,impacttoriverbanksandjettrajectory.Themainfindingsareasfollows.ThecriticalFroudenumberfortheflowchokingdecreaseswithincreasingoutletwidthoftheslit-typeenergydissipater.IftheflowFroudenumberisexpressedbytheparametersjustbeforethisenergydissipater,thetetrahedronplacedinsidethesidewalloftheoutletcouldefficientlyavoidtheflowimpacttotheriverbankofsameside,andcomparedwiththejettrajectoryoftheslit-typeenergydissipater,theoutletwithtetrahedronhasdifferenttrajectorytrend,i.e.,thedistanceofthejettrajectorydecreaseswiththeincreaseofthewaterheadduetospecialformoftheoutlettetrahedron.

  • 标签: 溢洪道 大单宽流量 低佛氏数 出口宽度 坝顶 液压
  • 简介:在这篇论文,在在低严肃下面的一辆矩形的坦克的液体sloshing的动力学被调查。基本频率和液体的sloshing的速度潜力被Fourier系列的扩大获得。力量的特征和液体作用于的时刻一辆矩形的坦克被分析。液体的sloshing的相等的机械模型ofspring-vibrator-damper与机械相等的原则被建立,数字结果被给。数字结果证明相等的sloshing团随严肃的增加增加,并且基本频率和相等的sloshing团随液体深度的增加增加。

  • 标签: 流体晃动 等效机械模型 基本频率 速度势能
  • 简介:Basedonthenon-Darcyflowcharacteristicsofsurfactantfloodinginthelowpermeabilityoilfield,consideringthechangesofthresholdpressureandinfluenceofsurfactantonconvection,diffusion,adsorptionandretention,amathematicalmodelisestablishedforathree-dimensional,two-phase,three-componentsurfactantflooding.Anewtreatmentforthechangesofthresholdpressureandanovelcorrectionmethodfortherelativepermeabilitycurveintheprocessofsurfactantfloodingarederived,whichenhancesthematchingdegreebetweenthemathematicalmodelandfieldpractice.ThemathematicalmodelwasusedtoperformthenumericalsimulationstudyforapilottestofsurfactantfloodinginChao45BlockofDaqingOilfield,aproperinjectionplanwasoptimized.Aftertheoptimizedplanwascarriedoutinoilfield,thedesirableeffects,likepressure-reducing,injectionrateincrease,andtheincreaseofoilrecovery,wereachieved.Theaverageoilincreaseforsinglewellreaches37%,theratioofcosttorevenueisabove1:4,sotheeconomiceffectofscaleispromising.

  • 标签: 表面活性剂 低渗透率 数字模拟技术 动力学
  • 简介:Thedynamicsofliquidsloshinginasphericaltankwithspacerunderlowgravitywasinvestigated.Byextendingthecharacteristicfunctions,thefrequenciesofliquidfree-sloshing,reactionforceandmomentsonthewalloftankwereobtained.Bymechanicalequivalentprinciple,theequivalentmodelsofspring-vibrator-damperofliquidsloshingweregiven.Thenumericalresultsobtainedshowwhenaspacerisinsertedinthetank,thesloshingfrequencyofliquidandthesloshingmassofliquidwilldecrease.

  • 标签: 微重力 液体晃动 等效力学模型 稳定性
  • 简介:Theboundaryelementmethod(BEM)isamainmethodforanalyzingtheinteractionsbetweenthewavesandthemarinestructures.AswiththeBEM,asetoflinearequationsaregeneratedwithafullmatrix,therequiredcalculationsandstorageincreaserapidlywiththeincreaseofthestructurescale.Thus,anacceleratedmethodwithalowstorageisdesirableforthewaveinteractionwithaverylargestructure.AsystematicreviewisgiveninthispaperfortheBEMforsolvingtheproblemofthewaveinteractionwithalargescalestructure.VariousintegralequationsarederivedbasedondifferentGreenfunctions,theadvantagesanddisadvantagesofdifferentdiscretizationschemesoftheintegralequationsbytheconstantpanels,thehigherorderelements,andthesplinefunctionsarediscussed.Forthehigherorderelementdiscretizationmethod,thespecialconcernsaregiventothenumericalcalculationsofthesingle-layerpotential,thedoublelayerpotentialandthesolidanglecoefficients.Foralargescalecomputationproblemsuchasthewaveinteractionwithaverylargestructureoralargenumberofbodies,theBEMswiththeFMMandpFFTaccelerationsarediscussed,respectively,includingtheprinciplesoftheFMMandthepFFT,andtheirimplementationsinvariousintegralequationswithdifferentGreenfunctions.Finally,somepotentialapplicationsoftheaccelerationmethodsforproblemswithlargescalecomputationsintheoceanandcoastalengineeringareintroduced.

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  • 简介:Thedynamiccharacteristicsofliquidsloshinginatransverselyvibratingsphericaltankwithspacerunderlowgravitywereinvestigated.Byexpandingthecharacteristicfunctions,thefrequenciesandvelocitypotentialsofliquidfree-sloshingwereobtained.Thedynamicequationsandboundaryconditionsofliquidsloshinginthetraversevibrationalsphericaltankwithspacerunderlowgravitywerederived.Bymodifyingthevelocitypotentialsofliquidfree-sloshing,thevelocitypotentialsofliquidsloshinginthetraversevibratingsphericaltankwithaspacerwereobtained.Furthermore,theforcesandthemomentsactingontankwallweregiven.Thenumericalresultsshowwhenaspacerisinsertedinthetank,thesloshingfrequenciesofliquidandtheforcesactingontankwallwilldecrease,butthemomentofforcetothecentreofthetankwhichiscausedbytheforceofliquidactingonthespacerwilloccur.

  • 标签: 水动力学 研究 发展 CFD
  • 简介:Undertheconditionoflowgravitythecharacteristicsofliquidforcedsloshinginaturningsphericaltankwithaspacerwereinvestigated.Thestaticshapeoftheliquidsurfacewasanalyzed.Byexpandingthecharacteristicfunctions,thefrequenciesandvelocitypotentialofliquidfree-sloshingwerederived.Thegoverningequationsandboundaryconditionsfortheforcedsloshingofliquidunderthetankturningwereestablished.Thetransverseforceofliquidactingonthetankandthemomentofforcetothecentreofthetankwhichiscausedbytheforceofliquidactingonthespacerweregiven.Numericalresultswerecomparedwiththeonesofthesphericaltankwithoutaspacer.Theresultsshowthatwhenaspacerisinsertedinthetank,thesloshingfrequencyofliquidandthetransverseforceofliquidactingonthetankwilldecrease,butthemomentofforcetothecentreofthetankwhichiscausedbytheforceofliquidactingonthespacerwilloccur.

  • 标签: 低重力 液体晃动 晃动抑制 球形容器
  • 简介:Flowdistributionheadersplayamajorroleinheatexchangers.Theselectionofheaderdiameter,branchpipediameter,branchpipespacingetc.isbasedonthedesigner'sexperienceandgeneralguidelines.Theproperselectionoftheheaderdimensionswillyielduniformflowdistributioninheatexchangers,whichinturnwillenhancetheheatexchangerefficiency.Inthiswork,theflowdistributioninbranchpipesandthepressurevariationacrossthebranchpipesinlaminarandlowturbulenceregionisstudiedwithtwomodelsoftheinletdividingheaders.Whenthenumericalanalysishasbeenapplied,itsinabilitytopredictthenoflowconditionthroughthebranchpipesisrevealed.Theresultsarepresentedintheformofflowrateratiothroughbranchpipesandnondimensionalcoefficientsacrossbranchpipeswhichareusefultoapplytheexistingmathematicalmodelsforthepresentexperimentalsetup.

  • 标签: 管壳式换热器 数值分析 流动分布 实验装置 层流 进气
  • 简介:Inthisarticle,thelowpressureaxialflowfanwithcircumferentialskewedrotorblade,includingtheradialblade,theforward-skewedbladeandthebackward-skewedblade,wasstudiedwithexperimentalmethods.Theaerodynamicperformanceoftherotorswasmeasured.Atthedesignconditionatoutletoftherotors,detailedflowmeasurementswereperformedwithafive-holeprobeandaHot-WireAnemometer(HWA).Theresultsshowthatcomparedtotheradialrotor,theforward-skewedrotordemonstratesawiderStableOperatingRange(SOR),isabletoreducethetotalpressurelossinthehubregionandmakemainloadingofbladeaccumulatinginthemid-spanregion.Thereisawiderwakeintheuppermid-spanregionoftheforward-skewedrotor.Comparedtotheradialrotor,inthebackward-skewedrotorthereishighertotalpressurelossnearthehubandshroudregionsandlowerlossinthemid-spanregion.Inaddition,thevelocitydeficitinthewakeisloweratmid-spanofthebackward-skewedrotorthantheforward-skewedrotor.

  • 标签: 空气动力学 性能 低压轴流排风机 桨叶 排流方式
  • 简介:Duringthedevelopmentoflowpermeabilityreservoirs.theinteractionbetweenfluidflowandrock-massdeformationisobvious.Onthebasisoffluidmechanicsinporousmediaandelasto-plastictheory.theauthorpresentsanequivalentcontinuummodeltosimulatefluidflowinfracturedlow-permeabilityoilreservoircoupledwithgeo-stress.Themodelnotonlyreflectstheporositychangeofmatrix,butalsothepermeabilitychangeduetotheopeningandclosingoffracture.Byanalyzingofsimulationresults,thechangesinporosityandpermeabilityandtheireffectonoildevelopmentarestudied.

  • 标签: 液固耦流 断裂低渗透性油库 多孔介质 数值模拟 相互作用 流体机械学