学科分类
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8 个结果
  • 简介:Sandjetinnon-Newtonianviscoplasticfluidisassociatedwithanumberofindustrialandengineeringapplications,includingsandcappingforthereclamationofoilsandstailingspondsandsedimentdepositionintosoftmud.Inthisstudy,severalexperimentswerecarriedoutbydepositingcircularsandjetsverticallyintoviscoplasticfluids,knownasLaponitegel.Thedeformationregimesofsandjetsinthegelwereinvestigated.Theyield-gravityparameterofthedeformedsanddropinthegelwascomputed.

  • 标签: 粘塑性流体 喷射流 填海工程 合成锂皂石 泥沙淤积 油砂
  • 简介:Theprobabilitydistributionsofsandparticles'lift-offandincidentvelocitiesinawind-blownsandfluxplayveryimportantrolesinthesimulationofthewind-blownsandmovement.Inthispaper,theverticalandthehorizontalspeedsofsandparticleslocatedat1.0mmaboveasand-bedinawind-blownsandfluxareobservedwiththeaidofPhaseDopplerAnemometry(PDA)inawindtunnel.Basedontheexperimentaldata,theprobabilitydistributionsofnotonlytheverticallift-offspeedbutalsothelift-offvelocityaswellasitshorizontalcomponentandtheincidentvelocityaswellasitsverticalandhorizontalcomponentscanbeobtainedbytheequaldistancehistogrammethod.Itisfound,accordingtotheresultsoftheχ2-testfortheseprobabilitydistributions,thattheprobabilitydensityfunctions(pdf's)ofthesandparticles'lift-offandincidentvelocitiesaswellastheirverticalcomponentsaredescribedbytheGammadensityfunctionwithdifferentpeakvaluesandshapesandthedownwindincidentandlift-offhorizontalspeeds,respectively,canbedescribedbythelognormalandtheGammadensityfunctions.Thesepdf'sdependonnotonlythesandparticlediameterbutalsothewindspeed.

  • 标签: 实验分析 沙微粒 入射速率 提升速率 可能性概率 环境空气动力学
  • 简介:Inordertoinvestigatetheinfluenceoftheverticalvibrationloadingontheliquefactionofsaturatedsand,onedimensionalmodelforthesaturatedsandwithaverticalvibrationispresentedbasedonthetwophasecontinuousmediatheory.Thedevelopmentoftheliquefactionandtheliquefactionregionareanalyzed.Itisshownthattheverticalvibrationloadingcouldinduceliquefaction.Therateoftheliquefactionincreaseswiththeincreaseoftheinitiallimitstrainorinitialporosityoramplitudeandfrequencyofloading,andincreaseswiththedecreaseofthepermeabilityorinitialmodulus.Itisshownalsothatthereisaphaselaginthesandcolumn.Whenthesandpermeabilitydistributionisnon-uniform,theporepressureandthestrainwillrisesharplywherethepermeabilityisthesmallest,andfracturemightbeinduced.Withthedevelopmentofliquefaction,thestrengthofthesoilfoundationbecomessmallerandsmaller.Inthelimitingcase,landslidesordebrisflowscouldoccur.

  • 标签: 融解 振动负载 饱和沙 断裂 固体力学
  • 简介:WesummarizeinthisoverviewachievementsincurrentresearchfrontiersinAsiansanddustwithemphasisonthemethodforsanddustresearch,thesourcesofsanddustaerosols,emissionofsanddust,mechanismofsanddustweather,chemicaltransformationduringtransport,andinfluencesonclimaticenvironmentandoceans.OurmainresultsshowthatmostofAsiansanddustcomesfromMongolia,theGobiDesert,aridandsemiariddesertareasinnorthwestChina,whichisdividedintoinitialsourcesandenhancedsources.HalfoftheglobalproductionofdustoriginatesfromAsiandustsourceregions.Asiandustweatherissoimmensethatitcancovera5-7-dayjourneyfromthesourcestotheKoreanPeninsula,JapanIslands,andthePacificOceantoevenimpactNorthAmerica.Asiandustweatherplaysanactiveroleinthebiogeochemicalcyclesoftraceelementsinthemid-latitudeNorthernHemisphere.

  • 标签: 沙尘气溶胶 气候环境 亚洲 源头 海洋 路线
  • 简介:Immersionofautomotivepartsinafluidizedbedoffoundrysandisusedtobothstripthecastingsfreefrommouldingsandandtoheat-treatthecastingsat500?C.Thefluidbedisheatedbyhotgasesfromaburnerdirectedfirstintoaserpentineheatexchangerlocatednearoneside-walloftherectangulartank,andthenintoadistributorconsistingofhorizontalspargerpipeshavingmaintenancestandpipesfixedintotheiruppersurfaces.

  • 标签: 铸造砂 流化床 应用 回收 整合 汽车零部件
  • 简介:Windblownsandfluxanddunefieldevolvingtowardtheoasishavebeenacommonecologicalandenvironmentalthreatconfrontedbymanycountries.Meanwhile,itisalsoakindofcomplexdynamicalprocessinvolvingmultipletemporalandspatialscaleswhichisstilloutofaccuratedescriptionthroughcurrentfieldobservations.Availablemodelsandreliablequantitativesimulationsareofsignificantvaluetopredictthespreadingrateofdesertificationandprovideanoptimaldesignforsandprevention.Thisp...

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  • 简介:Thecomplexityoftheloadsactingontheoffshorewindturbines(OWTs)structuresandthesignificanceofinvestigationonstructuredynamicsareexplained.Testresultsobtainedfromascaledwindturbinemodelarealsosummarized.Themodelissupportedonmonopile,subjectedtodifferenttypesofdynamicloadingusinganinnovativeoutofbalancemasssystemtoapplycyclic/dynamicloads.Thetestresultsshowthenaturalfrequencyofthewindturbinestructureincreaseswiththenumberofcycles,butwithareducedrateofincreasewiththeaccumulationofsoilstrainlevel.Thechangeisfoundtobedependentontheshearstrainlevelinthesoilnexttothepilewhichmatcheswiththeexpectationsfromtheelementtestsofthesoil.Thetestresultswereplottedinanon-dimensionalmannerinordertobescaledtopredicttheprototypeconsequencesusingelementtestsofasoilusingresonantcolumnapparatus.

  • 标签: 风电机组 动态行为 海上 支座 结构动力学 风力涡轮机