学科分类
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78 个结果
  • 简介:Thethermalperformanceofarectangularloopwithahorizontalheatingsegmentandapartlycoolingverticallegisstudied.Byone-dimensionalapproach,traditionalfrictionfactorandempiricalcorrelation,amodifiedGrashofnumberGr^*whichturnsouttobeveryimportantinthedescriptionofcirculationflowisintroduced.AnewcorrelationforNusseltnumberofthehorizontalheaterisobtainedandthecomparisonwithexperimentalvaluesshowsgoodagreement.

  • 标签: 热自然对流 环形热虹吸管 分析
  • 简介:Theinteractionbetweenwaveandhorizontalandverticalplatesisinvestigatedbytheboundaryelementmethod,andtherelationsofwaveexcitingforcewithplatethickness,submergenceandlengthareobtained.Itisfoundthat:1)Theefficientwaveexcitingforceexistswhileplatesubmergenceislessthan0.5m,andtheplateisverythinwithorderO(0.005m).2)Themaximumheavewaveexcitingforceexists,anditisthemainfactorforsurfaceandsubmergedhorizontalplatewhiletherollforcecanbeignored.3)Themaximumswaywaveexcitingforceexists,itisthemainfactorforsurfaceorsubmergedverticalplate,andtherollforceisabout20timesofhorizontalplate.

  • 标签: 板式 垂直 水下 波浪力 防波堤 散射
  • 简介:Themovementofwaterflowinunsaturatedfracturedrockwasinvestigatedwiththesandstonesamplethroughexperimentalresearchandnumericalsimulation.Theexperimentalresultsshowthatthearrivingtimeofwettingfrontisdelayedbythefracture,resultingintheincreaseofwatersaturationinthedomainontheupstreamsideofthefracture,whichwilllocallyenhancewaterflowthroughthematrix.Thenumericalsimulationwiththefinitevolumemethodcaptureseffectivelythesecharacteristics.Thecomparisonbetweensimulatedandobservedtraveltimeandarrivingtimeofwettingfrontshowsthattheirdifferenceareverysmallandthesimulatedresultsareinagreementwiththeobservedresults,whichimpliescalibratedparametersarereliableandeffective.Thenaccordingtothecalibratedparameters,fracturedmodelswereestablishedtoexaminehowthechangeoflargefracturedaperturewouldaffectthearrivingtimeofwettingfronts,pressureheadsandwatersaturationontheupstreamanddownstreamsidesoffracture.

  • 标签: 水流运动 骨折 含水饱和度 数值模拟 疗效 垂直
  • 简介:Inthepresenceofbottomwater,adropinthereservoirpressureduetofluidproductioncausestheaquiferwatertoexpandandtoflowintothereservoir.Therefore,hydrocarbonproductionfromawellislimitedbythecriticalflowrate.Themainpurposeofthisstudyistoinvestigatethebreakthroughtimeandthecriticalratebyusinganovel3-Dhorizontalwellmodel.Basedonthehypothesisthatthehorizontalwellislocatedinanypositionofacircularreservoirwithno-flowboundaryonthetopofthereservoirandconstantpressureboundaryatthebottom,thehorizontalwellhasbeenregardedasaninfiniteconductivitylinesinkandthena3-Dsteady-stateflowmodelofthehorizontalwellissetup.ApointsinkpressuresolutioncanbeobtainedwiththeFouriertransform.Theresultofthepressuredistributionoftheuniformfluxhorizontalwellcanbepresentedbymeansoftheprincipleofsuperposition.Accordingtothestablewatercrestingtheory,thisstudyconfirmsthestableheightofwatercrestingandthecriticalrate.Meanwhile,itcanre-confirmthebreakthroughtimeataspecificrate.Theoutputofacomparisonbetweenthis3-Dmodelandthereservoirnumericalsimulator(Eclipse)showsthemethodpresentedherecanbeappliedtoinvestigatethebehaviorofawatercrestingandtopredictthebreakthroughtimeatthebottomwaterdriverreservoir.

  • 标签: 动态分析软件 底水推进技术 临界流量分析 三维模型 水动力学
  • 简介:TherelateddataofGPSnetworksintheChinesemainlandanditsperipheralareasarecollectedfrominternetsitesinthepaper.AndvariousdatafusionmethodsarepresentedbasedonthecollectedGPSdata.ThustheunifiedhorizontalcrustalvelocityfieldscanbeestablishedintheChinesemainlandanditsperipheralareas.Theavailabledataof423GPSsitesareappliedtothevelocityfieldsanditsareagetsto1.2′107km2.Byanalyzingthevelocityfields,thebasicspatialdistributionfeatureofthehorizontalcrustalmotionintheChinesemainlandanditsperipheralareacanbeobtainedpreliminarily.Meanwhile,therangeofthevelocityfieldsintheChinesemainlandaffectedbythecollisionforceofIndiaplatetoEurasiaplateandtheproblemofprincipaldirectionoftheforcefromIndiaplatearediscussed.

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  • 简介:Theimpactsoftheenhancedmodel’smoistphysicsandhorizontalresolutionupontheQPFs(quantitativeprecipitationforecasts)areinvestigatedbyapplyingtheHIRLAM(highresolutionlimitedareamodel)tothesummerheavy-raincasesinChina.Theperformanceofthecontrolrun,forwhicha0.5°×0.5°gridspacingandatraditional“grid-boxsupersaturationremoval+Kuotypeconvectiveparamerization”areusedasthemoistphysics,iscomparedwiththatofthesensitivityrunswithanenhancedmodel’smoistphysics(Sundqvistscheme)andanincreasedhorizontalresolution(0.25°×0.25°),respectively.Theresultsshow:(1)Theenhancedmoistphysicsscheme(Sundqvistscheme),byintroducingthecloudwatercontentasanadditionalprognosticvariableandtakingintoaccountbrieflyofthemicrophysicsinvolvedinthecloud-rainconversion,doesbringimprovementsinthemodel’sQPFs.AlthoughthedeterioratedQPFsalsooccuroccasionally,theimprovementsarefoundinthemajorityofthecases,indicatingthegreatpotentialfortheimprovementofQPFsbyenhancingthemodel’smoistphysics.(2)Byincreasingthemodel’shorizontalresolutionfrom0.5°×0.5°,whichisalreadyquitehighcomparedwiththatoftheconventionalatmosphericsoundings,to0.25°×0.25°withoutthesimultaneousenhancementinmodelphysicsandobjectiveanalysis,theimprovementsinQPFsareverylimited.Withhigherresolution,althoughslightameliorationinlocatingtherainfallcentersandinresolvingsomefinerstructuresofprecipitationpatternaremade,thenumberofthemis-predictedfinestructuresinrainfallfieldincreaseswiththeenhancedmodelresolutionaswell.

  • 标签: quantitative precipitation forecasts(QPFs) moist PHYSICS RESOLUTION
  • 简介:WestudythroughelectromagneticmodelingtheabsorptionoflightofagivenwavelengthinanarrayofhorizontalInPnanowiresofdiameterlessthan100nm.Suchabsorptionisperformedmostefficientlybyusingpolarizedlightandbyexcitingacoupledopticalresonanceinasparsearray.Inthatcase,weexcitearesonanceintheindividualnanowiresandcoupletheresonancesinneighboringnanowiresthroughalatticeresonanceoftheperiodicarray.Atsucharesonance,anarraywithnanowiresof80nmindiametercanabsorbmorethaneighttimesmorestronglythanatight-packedarray,despitecontainingaseventimessmalleramountoftheabsorbingInPmaterial.

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  • 简介:Onthebasisofasinusoidalmodelofthedisturbedhorizontalacceleration,thespectrumcharacteristicsofmisalignedangleandhorizontalaccelerationcorrectionareanalyzed.Inanairbornegravimetrytest,themisalignedangleofplatformandhorizontalaccelerationcorrectionarecalculated.Theyare5'and3mGal,respectively,whentheflightisstable.

  • 标签: HACC 水平加速度修正 空气传播 重力测量 计算 范围分析
  • 简介:Naturalconvectionheattransferinahorizontalenclosurefilledwithanisotropicporousmedia,beingisothermallyheatedatbettomandcooledattopwhiletheverticalwallsbeingadiabatic,isnumericallystudiedbyapplyingtheBrinkmanmodel-amodifiedformofDarcymodelgivingconsideratiointotheviscouseffect.Theresultsshowthat:(1)alargerpermeabilityratio(K^*)causesalowerflowintensityintheenclosureandasmallerNusseltnumber,allNusseltnumbersapproachunityinthelimitofK^*→∞;alargerthermalconductivityratio(λ^*)causesastrangerdistortionofisothermsintheenclosureandahigherflowvelocitynearthewalls,alltheNusseltnumbersapproachunityinthelimitofλ^*-→0,thepermeabilityandthermalconductivityratiosgenerallyhaveopposingeffectsontheNusseltnumber.(2)anincreasingDarcynumberdecreasestheflowintensityandheattansferrates,whichismoresignificantatalowerpermeabilityratio.Inparticular,withK^*≤0.25,theNusseltnumberforDa=10^-3woulddifferfromthatofDarcyflowuptoanamountof30%,ananalysisneglectingthenon-Daricaneffectwillinevitablybeofconsiderableerror.

  • 标签: 热传导 自然对流 多孔介质
  • 简介:TheliftforcesonhorizontalcylindernearbottomisexperimentallyinvestigatdeatReynolds(Re)intherangelf2500~10000andKeulegan~CARPENTERNUMBERS(kc)intheintervalof5~20,andgapratio(e/D)isfrom(a0)areanalyzdebyusingtheFourieranalysesmethod.ItisfoundthatfoundthatbothCl&a0arethefunctionslftheKcnumber.

  • 标签: OSCILLATING flow horizontal cylinder LIFT forces
  • 简介:Afullsolutionoftwo-dimensionalNavier-Stokesandenergyequationwasconductednumericallytoanalyzethenaturalconvectionofthehorizontalstripwithanadiabaticsubstrate.Themainfeaturesofsuchconvectionare:(i)theleadingandtrailingedgeeffect,(ii)thenon-boundarylayereffect,and(iii)thesideedgeeffect.Theresultsarecomparedwiththeboundarylayertheoryandexprimentaldata.

  • 标签: 自然对流 电子器件 绝热衬底
  • 简介:TheanomalousreactionsofthegeomagnetichorizontalfieldtransferfunctionsbeforeTangshanearthquakeSHAOJINGGONG(龚绍京)HUARANCHEN(...

  • 标签: HORIZONTAL FIELD inter station TRANSFER FUNCTIONS
  • 简介:Themechanismfortransportingliquidfromthebottomofthepipetothetopstilltobeestablishedinthepredictionofthefilmthicknessdistributioninhorizontalannulartwo-phaseflow.Toresolvethisissue,usingfiveparallel-wireconductanceprobes,timerecordsoflocalliquidfilmthicknessatfivecircumferentialpositionswerecollected.Thecharacteristicsofcircumferentialliquidfilmthicknessprofilesanditsvariationwithgasandliquidvelocitieswereobtained.Thebasicfeaturesofprobabilitydistributionfunction,probabilitydensityfunction,auto-correlation,cross-correlationandpowerspectrumdensityfunctionofthedisturbancewavesinannularflowwerestudiedrespectively.Thecharactersticsofcircumferentialprofilesofdisturbancewavesanditsvariationwithgasandliquidvelocitieswerepresented.

  • 标签: 二相流 扰动波 流体薄层
  • 简介:Objective:Toinvestigatetheefficacyofquickrepositioningmaneuverforhorizontalsemicircularcanalbenignparoxysmalpositionalvertigo(H-BPPV).Methods:Clinicaldataof67patientswithH-BPPVwhounderwentquickrepositioningmaneuverinourhospitalfromJuly2009toNovember2014wereretrospectivelyanalyzed.Themaneuverinvolvedrotatingthepatientintheaxialplanefor180fromtheinvolvedsidetowardscontralateralsideasquicklyaspossible.Results:Completesymptomresolutionwasachievedin61patients(91.0%)atoneweekandin64patients(95.5%)at3monthspost-treatment.Duringtherepositioningmaneuverprocess,therewerenoobviousuntowardresponsesexcepttransientnauseawithorwithoutvomitinginafewpatients.Conclusion:TheresultsindicatethatthequickrepositioningmaneuverisaneasyandeffectivealternativetreatmentinthemanagementofHBPPV.

  • 标签: VERTIGO VESTIBULAR DISEASES Horizontal semicircular CANAL
  • 简介:Thenumericalinvestigationofregularwavesinteractingwithasubmergedhorizontaltwin-platebreakwaterispresentedinthispaper.Anumericalmodelwithanabsorbingwave-makerisestablishedbasedontheVOFmethod.Thevalidityofthemodelisverifiedbyexperimentalresults.Comparisonsbetweenthenumericalandexperimentalresultsshowthatboththewatersurfaceprofilesandthewave-inducedpressurescanbemodeledaccurately.Wavedeformationoverthebreakwater,waterparticlevelocitiesaroundthebreakwater,andthewave-inducedpressuresonthestructurearenumericallyinvestigated.Thepressureamplitudesofthefundamentalandsecondharmonicsonthemodelsurfaceareexaminedinvariouswaterdepths.Thecomputedandexperimentalresultshaverevealedthatthehigherfrequencycomponentsaregeneratedattheonshoresideofthebreakwater.Furthermore,thecomputedresultsdemonstrateacirculatingflowformedattheonshoresideofthebreakwater.

  • 标签: 数值模拟 相互作用 防波堤 卧式 数学模型 验证实验
  • 简介:首先,有不同坚硬的粒子的低速度的传送的特征试验性地以流动模式和压力落下在一条水平管道被调查证明蛞蝓流动能被分类进取决于沿着管道安定粒子的二种类型,并且没有解决的层,时期为蛞蝓流动是小的,它被叫独居的蛞蝓流动。为软粒子的压力落下被显示为难粒子比那大。然后,试验性的结果在证明从传送隧道的最高的表面的那个空气版本是为粒子的高集体的流动率的一个重要因素的好粉末的水平使流体化床的传送上被介绍。

  • 标签: 低速传输 水平流态床 粗糙颗粒 水平线
  • 简介:Throughmechanicalanalysis,animprovedhydraulicmodelforannularcuttingstransportwithfoamwasestablishedforhorizontaldrilling.Basedonthetwocriticalinclinationangles,theentirewellwasdividedintothreesegments.TheBagnoldstress,generalizedpowerlawrheologicalmodelandmodifiedhinderedparticlesettlingvelocityinfoamfluidwereadoptedinthemodeltoimprovethesimulationaccuracy.Theproposedmodelallowsmoreprecisepredictionofcuttingstransportpropertyinthewholerangeofwellinclinationangle.Modelperformancewasexaminedviacasestudyandexperimentaldata.Simulationresultsgivenbythepropulsioniterationandtrial-and-errormethodagreewellwithin-situhorizontalwelldrillingpracticeforthecasestudy,andthecomparisonbetweenthemodelpredictionandCapo’sexperimentaldatashowssatisfactoryagreement.

  • 标签: 水平井 泡沫流 钻孔切断 水力模型