简介：Inthispaper,perturbationmethodandFourier-cosine-expansionmethodareusedtosolvea3-DnonlinearproblemofasupercavitatingflowinaninclinedfieldofgravityatlargeFroudenumbers.Byexpandingthevelocitypotentialintoapowerseriesofasmallparameter,theoriginal3-Dnonlinearproblemisreducedtoanumberof2-Dones.Thesolutionsofthefirstthreeordersarederivedindetailandexpressedintermsofthecompleteellipticintegralsofthefirstandsecondkinds.Thentheboundaryintegralequationmethodisappliedtogetthenumericalsolutionsforeachorder.Computationalresultsareprovidedforsupercavitatingflowspastconesundervariousflowconditions.

简介：Inthepresenceofbottomwater,adropinthereservoirpressureduetofluidproductioncausestheaquiferwatertoexpandandtoflowintothereservoir.Therefore,hydrocarbonproductionfromawellislimitedbythecriticalflowrate.Themainpurposeofthisstudyistoinvestigatethebreakthroughtimeandthecriticalratebyusinganovel3-Dhorizontalwellmodel.Basedonthehypothesisthatthehorizontalwellislocatedinanypositionofacircularreservoirwithno-flowboundaryonthetopofthereservoirandconstantpressureboundaryatthebottom,thehorizontalwellhasbeenregardedasaninfiniteconductivitylinesinkandthena3-Dsteady-stateflowmodelofthehorizontalwellissetup.ApointsinkpressuresolutioncanbeobtainedwiththeFouriertransform.Theresultofthepressuredistributionoftheuniformfluxhorizontalwellcanbepresentedbymeansoftheprincipleofsuperposition.Accordingtothestablewatercrestingtheory,thisstudyconfirmsthestableheightofwatercrestingandthecriticalrate.Meanwhile,itcanre-confirmthebreakthroughtimeataspecificrate.Theoutputofacomparisonbetweenthis3-Dmodelandthereservoirnumericalsimulator(Eclipse)showsthemethodpresentedherecanbeappliedtoinvestigatethebehaviorofawatercrestingandtopredictthebreakthroughtimeatthebottomwaterdriverreservoir.

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简介：Inthisarticle,theanaglyphvideomakerisemployedforgeneratingrealistic3-DflowsandthesoftwareFlowAnimatorisdevelopedusingthattechnology.BasedonMicrosoftWindowsPresentationFoundation(WPF),thereal3-Dsceneissetupandmarkerparticlesaredistributedinitrandomlyinordertocreateamorenaturalflowscenario.ThetrajectoryoftheparticlemotioniscalculatedwithLagrangiandescriptionin3-Dspace.Duringthesimulation,theviewportcanbechangedinordertofocusondifferentpartsofthemodelbypanning,zooming,rotatingandinclinationvariationetc.Markerparticlesmayappearindifferentshapes:spheres,tracking-balls,cylindersandribbonsinordertofitdifferentflows.Itisthefirsttimethatthevideoanaglyphtechnologyisemployedinthe3-Dhydrodynamicsimulation,whichremovestheobstaclesfor3-Dscenestoberenderedonaflat-paneldisplay.

简介：Ageneralizedbendflowmodel,treatinga90°singlebendand60°continuousbends,wasdesignedtoquantitativelydescribe3-Dturbulencemechanismofcirculatingnot-fully-developedflowinopenchannelswithbends.The3-Dfluctuatingvelocitiesofturbulentflowweremeasuredandanalyzedwitha3-Dacoustic-Dopplervelocimeter.Formulafor3-Dturbulentintensitywasderivedusingthedimensionanalysisapproach.Expressionsofverticalturbulent-intensitydistributionswereobtainedwiththemultivariant-regressiontheory,whichagreewithexperimentdata.Distributionsofturbulentintensityandturbulentstresswerecharacterized,andtheirrelationshipswereconcluded.Inthebend-turbulent-flowcoreregion,longitudinalandlateralturbulent-intensitydistributionsarecoincidentwithlineardistribution,butinnear-wallregionarecoincidentwiththeGammadistribution.VerticalturbulentintensitydistributionsarecoincidentwiththeRayleighdistribution.Herein,itisconcludedthatthebendturbulenceisanisotropic.

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简介：A3-Dtimedomainmethodisdevelopedtoinvestigatethegapinfluenceonthewaveforcesfor3-Dmultiplefloatingstructures.Specialhydrodynamicresonanceduetosmallgapsbetweenmultiplefloatingstructuresonwaveforcesisexamined.Strongandcomplicatehydrodynamicinteractionsbetweenthefloatingbodiesareobservedandthenumericalcomputationshaveprovedtheexistenceofthesharppeakforceresponseoneachfloatingbodyatsomespecialresonantwavenumbers.Bycomparisonwiththeresultsfromthefrequencydomaintechnique,theresultsobtainedfromthetimedomainmethodrevealthesimilarresonantphenomenaandhydrodynamicinteraction.TheresonantwavenumbersarealsoprovedaroundkL=nπ(n=1,2,…,∞)withacorrespondingfrequencyshift.Thestronghydrodynamicinteractionfeatureispracticallysignificantforthedesignofmodulestructuresandthelinks(connection)inwholethefloatingbodysystem.

简介：Three-dimensionalseepageindoublefracturedmediawasmodeledinthispaper.Thedeterminationofhydraulicconductivitytensorofrockmassisavitalproblemfortheseawaterintrusionorseawaterencroachmentandseepageoffissuredmedium.Accordingtothegeologicalandhydrogeologicalconditionsforthe2nd-stageconstructionoftheThreeGorgesProject(TGP),thephysicalandmathematicalmodelsforthegroundwatermovementthroughthe3Ddoublefracturedmediaofrockmassduringconstructionwereestablishedinthispaper.Basedondiscontinuity-controlinversetheory,somerelatedparametersofdoublefracturedmediawereinversedwithfluxbeingtheknownquantityandcalibrationofwatertabletheobjectivefunction.Synchronously,theseepagefieldoftheconstructionregionwassystematicallyanalyzedandsimulated,theresultsofwhichexhibitthatthedoublefracturedmediamodeloffracturewatercancomprehensivelyandcorrectlydescribethegeologicalandhydrogeologicalconditionsintheconstructionregion.

简介：Thispaperisconcernedwiththewavesgeneratedbya3-Dbodyadvancingbeneaththefreesurfacewithconstantspeedinatwo-layerfluidoffinitedepth.ByapplyingGreen'stheorem,alayeredintegralequationsystembasedontheRankinesourcefortheperturbedvelocitypotentialgeneratedbythemovingbodywasderivedwiththepotentialflowtheory.Afour-nodeisoparametricelementmethodwasusedtotreatwiththesolutionofthelayeredintegralequationsystem.Thesurfaceandinterfacewavesgeneratedbyamovingballwerecalculatednumerically.Theresultswerecomparedwiththeanalyticalresultsforamovingsourcewithconstantvelocity.

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简介：Axisymmetricliquidjetshavebeenstudiedextensivelyformorethanonecentury,whilenon-axisymmetricjetsarealsoverycommoninengineeringapplicationsbutattractlessconcern.BasedonEulerianfluid-fluidmodelinFluentsoftware,thisarticleanalysizesthe3-DflowfieldsofpressureatomizerswithV-shapedcutatorifice,whichwillresultinanon-axisymmetricliquidjet.Flowrateanalysisandjetstructureanalysisarecarriedout,theresultsshowthattheflowratecanbeformulatedbyaddingacorrectioncoefficienttotheformulaofinviscidaxisymmetricjetsinatomizationregime,whentheWebernumberislowenoughtomaketheflowfalloutofatomizationregime,andthejetstructuretogetherwiththeflowrateformulawillchange.Analysisshowsthattheevolutionofthesprayandthereforethestructureoftheliquidjetareaffectedmuchbyrelativevelocityandthelocalvolumefractionofliquidphase.

简介：Twonear-fieldmethods,namelytheintegralmethodanddifferentialmethod,werepresentedforgivingsecond-ordermeandriftforcesandmomentsbetweentwofixedsubmergedbodiesinregularwaves.Fortheintegralmethod,withaseriesofmathematicalmanipulations,second-orderdriftforcesandmomentscouldbeeasilyexpressedbydistributedsourceswhichcouldbecalculatedbysourcedistributiontechniqueswiththeassumptionthattheamplitudeofshipmotionsaresmallonthebasisofthelinear3Dfrequencytheory.Forthedifferentialmethod,driftforcesandmomentscouldbeexpressedbythederivativeofvelocitypotentialwithrespecttospacecoordinate.Becausetwobodieswouldbehaveasasinglebodywhiletheclearanceisverylarge,thenumericalresultsofonesphereinsuchcaseweregivenandcomparedwithanalyticalresultsofasinglespherewhichdoesnotinvolvetheeffectoffreesurface.Whensubmergeddepthbecomesenoughlarge,agoodagreementcanbereached.Thentheintegralmethodwasusedtopredictthesecond-orderdriftforcesandmomentsoftwosubmergedspheresandspheroidswithasmalllateralseparationdistanceinwavescomparedwiththenumericalresultsobtainedbythedifferentialmethodandtheyagreewell.Bycomparison,itindicatestheinteractioneffectsbetweentwosubmergedbodieshaveaprofoundinfluenceonthedriftforcesandmoments.Inthispaper,theforwardspeedeffectonsubmergedsphereswasalsoconsidered.

简介：为了保证矿山安全高效开采,通过分析影响采场稳定性关键因素及破坏机理,应用数值模拟法对二步矿柱在不同结构参数和两侧不同充填配比开采条件的稳定性进行分析,优选出安全高效的一步采场充填配比和二步采场的结构参数。采用FLAC3D数值模拟,计算和分析在开采过程中,不同结构参数和两侧不同充填配比的采场顶板的应力、应力分布区域面积及位移变化特征,得出各不同方案的采场顶板稳定情况。结果表明：采场受两侧充填体配比的影响较为明显,一步采场灰砂比由1∶6改变到1∶8时,对二步采场的稳定性影响较小;灰砂比小于1∶8和采场宽度大于18m时,采场顶板的拉应力和位移的变化率逐渐变大,采场的稳定性迅速降低。因此,综合矿山生产安全、高效及成本考虑,建议一步采场充填配比为1∶8、二步采场的宽度为18m。

简介：三门核电循环水泵房基坑为超深基坑（最深处为32．3m），处于基岩面埋藏较浅且上部覆盖较厚淤泥层和回填石层的特殊区域。本工程依据地层条件，将基坑边坡划分为完全基岩边坡、基岩埋深浅且无淤泥地层的边坡、基岩埋深较大且有较厚淤泥层的边坡3种类型。分别采用3种支护型式：放坡、排桩＋岩锚、排桩＋深搅重力墙＋岩锚，有效解决了滨海软土区的地下水位高，淤泥质软土黏聚力及内摩擦角小，基坑侧壁受水平荷载大、易失稳等难题。典型断面计算结果表明，锚拉力最大为361．84kN；基坑侧壁最大水平位移为19．26mm，支护桩最大正负弯矩值为711．36kN·m和-787．52kN·m，基坑顶部最大沉降量为50mm，均满足设计与规范要求。

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.

简介：河北省黄壁庄水库管理局紧密围绕省水利厅党组决策部署,把作风整顿暨一问责八清理专项行动作为推动水库管理改革发展的重要载体,精心谋划,细化措施,扎实推进各项工作,取得了明显成效。1.认真履行“两个责任”,确保不走形式过场一是认真履行党委主体责任。3次召开党委会、4次召开局务会、5次召开作风办会议,

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简介：影响TBM掘进的主要因素有地质因素，隧道设计因素，隧道TBM设计因素等，进行TBM掘进循环进尺计算要充分考虑这些因素以及其他不确定因素，主要计算项目有：纯掘进速度，掘进行程，切削刀寿命，切削刀单位掘进体积和循环时间。

简介：区域良性水循环的核心内容是节水、雨水利用和中水回用(包括污水处理)的集成应用,开源节流相结合,通过水的循环利用,提高用水效率,争取达到零排放的目标.本文在区域良性水循环理论研究的基础上,选择北京市怀柔应急水源地进行示范,完成了节水、办公楼及路面的雨水收集和利用系统,中水处理及回用系统,绿地灌溉系统的集成应用,提出了小区域水资源高效利用、零排放的良性循环模式.在示范区内,下雨时路面不产生积水,生活污水被全部处理和应用,绿地灌溉均采用处理后的水,植物长势良好,充分体现了水在小区域的良性循环,该模式对整个北京市的大区域良性水循环的建立具有一定的借鉴和示范作用.