简介:Atheoreticalstudywasconductedtocharacterizehydraulicjumpoflaminarcircularliquidjets.Theobjectiveofthisresearchwastodeterminethejumplocationinasimpleexplicitform,Theeffectsofmanyfactorswereinvestigatedincludingnozzlediameter,jetexitpressure,nozzle-to-platespacing,jetvelocityandReynoldsnumber,ItwasfoundthatthetheoreticaldatacollapsedwellovertherangeofjetReynoldsnumber500≤Re≤1800withpreviousdata.
简介:Tortuosityisoneofthekeyparameterstocharacterizethetransportpropertiesofporousmedia.Therearemanymodelsfortortuosityestimationbasedonsomedefinitions:geometric,hydraulic,electric,anddiffusivedefinitions.However,relationshipsamongthosetortuositiesremainunclearduetothelackofdirectcomparisononthesameporousmedia.HerewefocusonhydraulicandelectrictortuositiesandhaveconductedaseriesoffiniteelementsimulationswiththeNavier–Stokesequationandtheequationforelectriccurrenttodirectlycomparetortuosities.Theresultsrevealedthat:(1)onaverage,hydraulictortuosityis15%greaterthanthatoftheelectricone;(2)theproposedmodelbasedonthevanGenuchten-typefunctionsuccessfullyapproximatesbothhydraulicandelectrictortuosities;(3)tortuositiesobtainedfromtheporousmediapackedwithcircularparticlesandsquareparticlesshowquantitativelysimilartrends.
简介:Consideringutilizationoftheoriginalchromium-bronzematerial,twoprocessingtechniquesincludinghydraulicexpansionandhightemperaturevacuumweldingwereproposedfortheoptimizationofheat-sinkstructureinEAST.Theheattransferperformanceofheat-sinkwithorwithoutcoolingtubewascalculatedanddifferenttypesofconnectionbetweentubeandheat-sinkwerecomparedbyconductingaspecialtest.Itisshownfromnumericalanalysisthatthediameterofheat-sinkchannelcanbereducedfrom12mmto10mm.Comparedwiththeoriginalsample,thethermalcontactresistancebetweentubeandheat-sinkforweldingsamplecanreducetheheattransferperformanceby10%,whileby20%forthehydraulicexpansionsample.However,theweldingtechniqueismorecomplicatedandexpensivethanhydraulicexpansiontechnique.Boththeprocessingtechniqueandtheheattransferperformanceofheat-sinkprototypeshouldbefurtherconsideredfortheoptimizationofheat-sinkstructureinEAST.
简介:Thispaperpresentsastudyofthemovementandthehydrodynamicperformanceofanewtide-poweredhydraulicturbinethroughnumericalsimulations.Bymeansofthemovingmeshmethod,theopen-closedsequencesofthebladesandthemovementoftherotorsareobtainedandtheangularvelocityandtheaverageenergyutilizationcoefficientunderdifferenttipspeedratiosarealsoobtained.Moreover,theoptimumtipspeedratioisidentifiedbyintegratingtheoutputpowerandtheenergyutilizationcoefficientofthehydraulicturbinewithdifferenttipspeedratios,providingdatasupportfortheprototypedesignofthehydraulicturbine.
简介:Two-DimensionalModelofHydraulicFracturinginGeosciences:Effects of Fluid BuoyancyYoshitoNakashima;MitsuhiroToriumi(GeologicalI...
简介:Hardwareintheloopsimulation(HILS)hasbeeninvestigatedinthefieldofthemultibodydynamics(MBD),whichcombinedtheMBDsimulationwiththeactualmechanicalsystem.ThefastsimulationisnecessaryfortheHILSsysteminordertorequiretherealtimesimulation.Thispaperpresentsafastsimulationtechniqueusingthedomaindecompositionmethodwiththeiterationintheflexiblemultibodysysteminwhichflexiblelinkagesystemandelectro-hydraulicdrivesystemarecoupledwitheachother.
简介:为切入的流的隧道可变性的水力的几何学上的盆水文学的效果为Yazoo河盆用可得到的领域数据集合和分水岭水文学和隧道hydraulics的模型被调查,美国。学习用简单线性回归作为排水区域的功能在满满的分泌物介绍满满的分泌物,隧道宽度,吝啬的深度,代表性的区域,纵的斜坡,单位溪流力量,和吝啬的速度的水力的几何学关系。水力的几何学关系为61条溪流被开发,当隧道进化模型(CEM)打IV和V,他们中的41个是CEM溪流类型II和III,他们中的20个被分类。这些关系对无价水力并且水资源工程师,水文学者,和geomorphologists在溪流恢复和保护包含了。这些关系能被用来在一条溪流隧道的比较稳定性的未计量的分水岭以及评价在满满的舞台和溪流尺寸的地鉴定帮助。一套水力的几何学关系在这研究被介绍,这些实验关系为稳定、切入的隧道描述物理关联。代表性的区域,联合隧道宽度和吝啬的隧道深度的效果,被发现对在排水区域和满满的分泌物的变化高度应答。与在排水区域和满满的分泌物的变化一起的代表性的区域,隧道宽度,吝啬的隧道深度,和吝啬的速度的分析比是吝啬的隧道深度或吝啬的速度的显示隧道宽度对在排水区域和满满的分泌物的变化更应答。
简介:Thegeneralconceptofdatacompressionconsistsinremovingtheredundancyexistingindatatofindamorecompactrepresentation.Thispaperisconcernedwithanewmethodofcompressionusingthesecondgenerationwaveletsbasedontheliftingscheme,whichisasimplebutpowerfulwaveletconstructionmethod.Ithasbeenprovedbyitssuccessfulapplicationtoareal-timemonitoringsystemoflargehydraulicmachinesthatitisapromisingcompressionmethod.
简介:Thepier,placedattheoutletofthepressureflowsection,isaneffectivedesigntodealwiththeproblemsofthemanufactureandoperationofthegatesforadischargetunnelwithhighwaterhead.Itiscrucialtocontrolthewater-wing,inducedbythistypeofthepier.Throughobservingthephenomenaofthewater-wing,thereasonofthewater-winginception,i.e.,theconcaveoftheflowsurface,waspresented,andatypeofthenewpierwithbottomunderlaywasdesigned.Thehydrauliccharacteristicsofthepier,includingthevariationsofthewater-wingfeatures,bothlengthandheight,withthewaterhead,aswellaswiththeconcavedepth,andwiththeheightofthebottomunderlay,andthevariationsoftheconcavedepthwiththeheightofthebottomunderlay,wereinvestigatedbyphysicalmodelexperiments.Theresultsshowthattheapproachofthemodificationoftheconcavethroughthestructureswiththebottomunderlay-typepierisremarkablyeffectiveinthewater-wingcontrol.
简介:在为低温度、浅、高的冰点油水库折断处理期间,首要的问题是由注射冷液体克服uncompleted故障,折断液体的uncompletedcleanup和形成的冷损坏。避免那些问题,采用被建议一新包含了在这篇论文描述了的产生热的水力的断裂液体系统。第一,二种化学产生热的系统我们再学习,NH_4Cl-NaNO_2系统被选择。根据系统的反应特征,草酸酸被选择为反应的催化剂并且包含由阶段分离方法把乙醇纤维素和石蜡用作涂层材料。有折断液体的hydroxypropyl-guar的NH_4Cl-NaNO_2-encapsulated草酸酸的相容性也在论文被讨论。结果证明包含的水力的断裂液体包含了heat-generatingagents兔好稳定性和相容性。当断裂的液体包含2.0摩尔·L~时(-1)NH_4Cl-NaNO_2,0.93%每硫酸盐包含了草酸酸和0.08%铵,山峰温度罐头到达78.0℃和剩余液体的粘性是在4个小时以后的3.12mPa·s。
简介:Throughmechanicalanalysis,animprovedhydraulicmodelforannularcuttingstransportwithfoamwasestablishedforhorizontaldrilling.Basedonthetwocriticalinclinationangles,theentirewellwasdividedintothreesegments.TheBagnoldstress,generalizedpowerlawrheologicalmodelandmodifiedhinderedparticlesettlingvelocityinfoamfluidwereadoptedinthemodeltoimprovethesimulationaccuracy.Theproposedmodelallowsmoreprecisepredictionofcuttingstransportpropertyinthewholerangeofwellinclinationangle.Modelperformancewasexaminedviacasestudyandexperimentaldata.Simulationresultsgivenbythepropulsioniterationandtrial-and-errormethodagreewellwithin-situhorizontalwelldrillingpracticeforthecasestudy,andthecomparisonbetweenthemodelpredictionandCapo’sexperimentaldatashowssatisfactoryagreement.
简介:Apre-filtercombinedwiththresholdself-learningwaveletalgorithmisproposedforhydraulicpressuresignalsdenoising.Thedenoisingthresholdisself-learntinthesteadyflowstate,andthenmodifiedunderagivenlimittomakethemeansquareerrorsbetweenreconstructionsignalsanddesirableoutputsminimum,sothecorrespondingoptimaldenoisingthresholdinasingleoperatingcasecanbeobtained.Theseoptimalthresholdsareusedforthewholesignaldenoisingandaredifferentinvariouscases.Simulationresultsandcomparativestudiesshowthatthepresentapproachhasanobviouseffectofnoisesuppressionandissuperiortothoseoftraditionalwaveletalgorithmsandback-propagationneuralnetworks.Italsoprovidestheprecisedataforthenextstepofpipelineleakdetectionusingtransienttechnique.
简介:Thepaperdescribesapermeametertestmethodfordeterminationofthehydraulicconductivity(AT)alongmulti-directionsinfluvialsedimentswithcrossbeddings.Unlikeexistingin-situpermeametermethodsthatdeterminehydraulicconductivityforsubmergedstreambeds,ourmethodwasintendedtomeasurehydraulicconductivityofexposedstreambedsorfluvialsediments.ThemethodwasappliedtotheWeiRiver,ShaanxiProvince,CentralChinaforcharacterizationoftheanisotropyofKinawell-sortedfluvialsediment.Theresultsillustratedthateveninwell-sortedsediments,cross-beddingandsedimentfabrication(ortexture)canleadtovariedKvaluesalongdifferentmeasurementdirections.TheKvaluewasthelargestalongthedipdirection(orthemajordirection)thatisparalleltotheorientationofcrossbeddingandthesmallestinthedirectionperpendiculartothebedding(ortheminordirection).TheKvalueinagivendirectionbetweenthemajorandminordirectionoftenfellintherangeboundedbytheKvaluesinthemajorandminordirections.TheanisotropyratioofK(theratioofKvaluebetweenthemajorandminordirections)intwotrenchesforthiswell-sortedfluvialsedimentwasupto1.14to1.23,respectively.Ourresultsalsodemonstratedthatevenforwell-sortedsediments,theKvaluesbetweentwosamplingpointsonlyabout10cmapartcandiffer.ItisclearthattheKdistributionstronglycorrelatestothebeddingorientation.
简介:TheturbulenceflowFreeSurfacehasimportantapplicationsinhydraulicspillwaysstructure,suchasthehydraulicjump,energydissipationflowetc.Thisisbeingconsideredasverycomplicatedflow,andhasnotyetbeensolvedquitewellbynumericalmethod.Inthispaper,aLarge-scalecomputationalsoftwarepackagearedevelopedfornumericallaboratoryofhydraulicspillwaystructure.Somemethods,suchasturbulencemodel,freesurfaceandirregularboundarytreatingtechniques,scientificcomputervisualizationareputforwardandperformed.
简介:Inthispaper,ahorizontal2-Dnumericalmodelhasbeendevelopedtosimulateflowprocessesindikeburst.Thefinitedifferencemethodisusedincomputation.Themodelemploys2-Dflowequationsandcansimulatecomplexflowswhensupercriticalflowandsub-criticalflowexistsimultaneouslysuchashydraulicjumps.Severalsimulatedresultsareworkedouttodemonstratetheapplicabilityofthenumericalmodel,suchasfloodpropagationonadrybedofacomplexterrain.