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13 个结果
  • 简介:Thestudyofcylindricalparticulateflowshaswideindustrialapplicabilityandhencereceivedmuchattention.Thepurposeofthepresentpaperistoprovideareviewonthemotionofcylindricalparticlesinshearlayer,convergingchannelandjetflows,thedynamicofcylindricalparticlessedimentationinaNewtonianfluid,thecharacterizationofturbulentcylindricalparticulateflows,thepropertyofinteractionbetweentheparticles,thestructuralfeatureandrheologyofsuspensions,theanalysisofhydrodynamicinstabilityofcylindricalparticlesuspensions.Finally,theconcludingremarksaregiven.

  • 标签: 柱面散式流 切变层 射流 时滞动力学
  • 简介:SHIPHYDRODYNAMICSBASICRESEARCHINTHEUNITEDSTATES¥EdwinP.Rood(MechanicsandEngergyConversion(333),OfficeofNavalResearchArlington...

  • 标签: SHIP performance SHIP HYDRODYNAMICS COMPUTATIONAL FLUID
  • 简介:Thispapergivesemphasisontheresearchoftheproblemoflocalheadlossofcrossfractureflowbyalotofmodelexperiments,andatheoreticalmodeloflocalheadlossofcrossfractureflowisfoundedbyuseofthemomentumlawofwaterflow.Throughthecorrelationanalysisbetweenmodelexperimentalresultsandtheoreticalmodel,thecorrectioncoefficientoftheoreticalmodelisdefinite.Theproposedcalculationformulaoflocalheadlossofcrossfractureflowcanbeusedtoanalyzetheproblemofnetworkfractureseepage.

  • 标签: CROSS FRACTURE model EXPERIMENT LOCAL head
  • 简介:Thepaperconcernswiththedesignphilosophy,feasibilitystudy,aswellassomepeculiarfeaturesofIWHRwatertunnelforcavitationresearch.Thehighlightsworth-mentioningarethemaximumvelocityof35m/sandReynoldsnumberof1×10~7aswellastheprovisionofaspeciallydesignedairresorber.

  • 标签: PROVISION REYNOLDS PECULIAR tunnel PHILOSOPHY specially
  • 简介:Aseriesofprojectileandwater-tunnelexperimentswereconductedtoinvestigatetheshapecharactersofnaturalandventilatedsupercavitation.Itwasfoundthattheshapeanddimensionsofboththenaturalsupercavitationandtheventilatedsupercavitationaresimilarthroughthecomparisonofthemwhenthecavitationnumberissmallandequal,andthecontourofboththenaturalsupercavitationandtheventilatedsupercavitationcanbecalculatedeffectivelywiththeSavchenkoformula.Thegravityeffectcaninducetheasymmetryofventilatedsupercavitation,andtheasymmetryismoreapparentastheFroudenumberissmaller.Theempiricalformulaforcalculatingtheaxialdeformationofventilatedsupercavitationwascorrectedandexpandedbasedonexperimentdata.Theevolutionrulesofboththenaturalsupercavitationandtheventilatedsupercavitationweredescribed,andthevortexfrequencyofnaturalcavitationwasobtained.Inaddition,thehystereticaspectwasobservedbetweenthedevelopmentandthefallprocessofventilatedcavitation.

  • 标签: 自然空化流动 超空化流动 水渠试验 抛物试验
  • 简介:从两倍圆柱的结构的放射的一个实验在anopen空气池溏里被保持。从驾驶的驾驶模型和two-pointstochastic力量建模的一个点泛音力量的放射回答被测量。数字结果与试验性的结果显示出一个好协议。可能的错误被分析。

  • 标签: 声学 辐射 实验 双重圆柱结构
  • 简介:Duringthedesignandconstructionofthedeepwateroffshorebasin,itscurrentgenerationsystemisconsideredtobeoneofthekeytechnologies.Inthisarticle,thestate-of-the-artdeepwateroffshorebasinatShanghaiJiaotongUniversitywasexaminedasacasestudy.Different3-Dnumericalmodelsofthecurrentgenerationsystemweredevelopedandcalculated.Theuniformityofflowfieldinthebasin,suchashorizontalandverticalcurrentvelocityprofiles,werecalculatedindetail.Besides,a1:10scaledmodeltestwasalsocarriedout.Thecurrentvelocitiesatdifferentlocationsinthebasinweremeasuredandcomparedwiththecalculatedresults.Itisconcludedthatsatisfactoryagreementcanberesultedbetweenthenumericalsimulationandmodeltest.Inaddition,itissuggestedthattransitionsectionsandturningvanesneedtobesetininflowandoutflowculvertstoimprovetheuniformityofflowfieldinthebasin.Andthehydraulicperformanceofthedeepwatercurrentgenerationsystemcanmeettherequirementsofmodeltestsindeepwater.

  • 标签: 电力系统 海洋发电 海洋开发 模型试验
  • 简介:BasedonGreen’stheorem,atimedomainnumericalmodelwasconstructedtosimulatewavemakingphenomenoncausedbyamovingship.Inthisarticle,theRankinesourcesanddipoleswereplacedonboundarysurfaces(i.e.,theshipsurfaceandfreesurface),andatime-steppingschemewasemployed.Itsuniquecharacteristicisthatsteadystatecanberealizedfrominitialvaluebyemployingthetime-steppingschemeandunsteadyfreesurfaceconditions.Intimedomain,iftheresultsofunsteadyflowproblemtendtodatastabilizationaftermanytimestepsofcomputation,theycouldberegardedasthedataofsteadyones.Thismodelcouldbeemployedtosteadyorunsteadyproblems.Theoreticalreasoningandcomputationalprocessofthismethodwasdescribedindetail.Thelinearandnonlinearboundaryconditionsonbodysurfacewerestudied,andtherelativemeanstorealizetheseboundaryconditionsiniterativecomputationwerealsodiscussed.SomeproperparametersaboutthemodeloftheWigleyhullweredeterminedbymanynumericaltests,andtheirinfluencesonwavemakingresistanceandwavepatternwerediscussed.Accordingtothecomparisonbetweennumericalresultsanddataavailableinrelativereferences,themethodusedinthisworkisproventobeareliablemethodintimedomain.Andthelatticereorganizationineverytimestepcomputationisafeasiblenumericalapproach.

  • 标签: 兰金 偶极子 格子 波形
  • 简介:Inthispaper,astudyofthehigh-speedgasjetofarocketnozzleunderwaterwascarriedoutusingcommerciallyavailableCFDsoftwareFLUENTwithit'suser-defined-function.Thevolumeoffluidtechniquebasedonfinitevolumemethodwasadoptedtosolvethetime-dependentmultiphaseflowincludingacompressiblephase,andthePISOalgorithmwasincluded.Thecomputedresultsshowthatthisproblemwascalculatedsuccessfully.Thegasbubblebehindthenozzle,andthewavestructureexistinginhighlycompressedgasinwaterwerecapturedaccurately.

  • 标签: 水下火箭喷嘴 PISO算法 波结构 多孔气泡 气体射流
  • 简介:Atime-domainKelvinsourcehigh-orderpanelmethodbasedonNURBSisdevelopedandappliedtosolvetheunsteadywave-makingproblems.Numericalresultsofinstantwaveresistanceandfreesurfaceelevationarepresentedandcomparedwiththeavailabyresultsbyotherauthors,forsubmergedspheroidandspherebeneaththefreesurfaceandforsurfaceshipofWigleymodelsmovingwithunsteadyspeed.Theagreementissatisfying.

  • 标签: 时间因素 数值仿真 不稳定船舶波动 NURBS 高阶镶嵌法
  • 简介:Thecut-offnegativepressuremethodisoneofeffectiveapproachestosolvetheseepageflowwithfreesurface.Accordingtothecharacteristicsofthismethod,however,ithasbeenfoundoutthatthedeficiencyofthealgorithmsistoeasilycauseinaccuratesimulationinthevicinityoffreesurfaceowingtothepenaltyfunctionwithonlyonecontrollingpenaltyparameter.Therefore,animprovedcut-offpressuremethodwaspresentedbyconstructingpenaltyfunctionwithtwocontrollingpenaltyparameters.Theimprovedalgorithmswereillustratedtobeabletoimprovethesimulationaccuracyandraisetheconvergencespeedthroughconsideringtheeffectsofthepartiallysaturatedorunsaturatedelementsmorereasonablyandcalculatingthenodalexternalforcesmoreaccurately.Finally,theimprovedcut-offnegativepressuremethodwasappliedtothesimulationofunsteadyseepageflowwithfreesurface,andthecorrespondingprogramcodesweredevelopedwithvalidationofsomecases.

  • 标签: 自由表面 定点压力 渗流 有限元分析 处罚函数
  • 简介:Thispaperstudieswaterandsolutetransportinsoil.ItmainlydealswiththeadsorptionbehaviorofheavymetalCd++insoilatdifferentPHvaluesandthedynamiccharac-tersofadsorptionprocessinunsaturatedstate.Throughtheoreticalanalysisandexperimentalre-search,theadsorptionisothermandtheequationsofdynamicadsorptioninsaturatedandunsatu-ratedstatesareproposed.

  • 标签: SOIL adsorption dynamics UNSATURATION experiment
  • 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