简介:Thethermalperformanceofarectangularloopwithahorizontalheatingsegmentandapartlycoolingverticallegisstudied.Byone-dimensionalapproach,traditionalfrictionfactorandempiricalcorrelation,amodifiedGrashofnumberGr^*whichturnsouttobeveryimportantinthedescriptionofcirculationflowisintroduced.AnewcorrelationforNusseltnumberofthehorizontalheaterisobtainedandthecomparisonwithexperimentalvaluesshowsgoodagreement.
简介:Theinteractionbetweenwaveandhorizontalandverticalplatesisinvestigatedbytheboundaryelementmethod,andtherelationsofwaveexcitingforcewithplatethickness,submergenceandlengthareobtained.Itisfoundthat:1)Theefficientwaveexcitingforceexistswhileplatesubmergenceislessthan0.5m,andtheplateisverythinwithorderO(0.005m).2)Themaximumheavewaveexcitingforceexists,anditisthemainfactorforsurfaceandsubmergedhorizontalplatewhiletherollforcecanbeignored.3)Themaximumswaywaveexcitingforceexists,itisthemainfactorforsurfaceorsubmergedverticalplate,andtherollforceisabout20timesofhorizontalplate.
简介:Themovementofwaterflowinunsaturatedfracturedrockwasinvestigatedwiththesandstonesamplethroughexperimentalresearchandnumericalsimulation.Theexperimentalresultsshowthatthearrivingtimeofwettingfrontisdelayedbythefracture,resultingintheincreaseofwatersaturationinthedomainontheupstreamsideofthefracture,whichwilllocallyenhancewaterflowthroughthematrix.Thenumericalsimulationwiththefinitevolumemethodcaptureseffectivelythesecharacteristics.Thecomparisonbetweensimulatedandobservedtraveltimeandarrivingtimeofwettingfrontshowsthattheirdifferenceareverysmallandthesimulatedresultsareinagreementwiththeobservedresults,whichimpliescalibratedparametersarereliableandeffective.Thenaccordingtothecalibratedparameters,fracturedmodelswereestablishedtoexaminehowthechangeoflargefracturedaperturewouldaffectthearrivingtimeofwettingfronts,pressureheadsandwatersaturationontheupstreamanddownstreamsidesoffracture.
简介:Inthepresenceofbottomwater,adropinthereservoirpressureduetofluidproductioncausestheaquiferwatertoexpandandtoflowintothereservoir.Therefore,hydrocarbonproductionfromawellislimitedbythecriticalflowrate.Themainpurposeofthisstudyistoinvestigatethebreakthroughtimeandthecriticalratebyusinganovel3-Dhorizontalwellmodel.Basedonthehypothesisthatthehorizontalwellislocatedinanypositionofacircularreservoirwithno-flowboundaryonthetopofthereservoirandconstantpressureboundaryatthebottom,thehorizontalwellhasbeenregardedasaninfiniteconductivitylinesinkandthena3-Dsteady-stateflowmodelofthehorizontalwellissetup.ApointsinkpressuresolutioncanbeobtainedwiththeFouriertransform.Theresultofthepressuredistributionoftheuniformfluxhorizontalwellcanbepresentedbymeansoftheprincipleofsuperposition.Accordingtothestablewatercrestingtheory,thisstudyconfirmsthestableheightofwatercrestingandthecriticalrate.Meanwhile,itcanre-confirmthebreakthroughtimeataspecificrate.Theoutputofacomparisonbetweenthis3-Dmodelandthereservoirnumericalsimulator(Eclipse)showsthemethodpresentedherecanbeappliedtoinvestigatethebehaviorofawatercrestingandtopredictthebreakthroughtimeatthebottomwaterdriverreservoir.
简介:TherelateddataofGPSnetworksintheChinesemainlandanditsperipheralareasarecollectedfrominternetsitesinthepaper.AndvariousdatafusionmethodsarepresentedbasedonthecollectedGPSdata.ThustheunifiedhorizontalcrustalvelocityfieldscanbeestablishedintheChinesemainlandanditsperipheralareas.Theavailabledataof423GPSsitesareappliedtothevelocityfieldsanditsareagetsto1.2′107km2.Byanalyzingthevelocityfields,thebasicspatialdistributionfeatureofthehorizontalcrustalmotionintheChinesemainlandanditsperipheralareacanbeobtainedpreliminarily.Meanwhile,therangeofthevelocityfieldsintheChinesemainlandaffectedbythecollisionforceofIndiaplatetoEurasiaplateandtheproblemofprincipaldirectionoftheforcefromIndiaplatearediscussed.
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.
简介:WestudythroughelectromagneticmodelingtheabsorptionoflightofagivenwavelengthinanarrayofhorizontalInPnanowiresofdiameterlessthan100nm.Suchabsorptionisperformedmostefficientlybyusingpolarizedlightandbyexcitingacoupledopticalresonanceinasparsearray.Inthatcase,weexcitearesonanceintheindividualnanowiresandcoupletheresonancesinneighboringnanowiresthroughalatticeresonanceoftheperiodicarray.Atsucharesonance,anarraywithnanowiresof80nmindiametercanabsorbmorethaneighttimesmorestronglythanatight-packedarray,despitecontainingaseventimessmalleramountoftheabsorbingInPmaterial.
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简介:Onthebasisofasinusoidalmodelofthedisturbedhorizontalacceleration,thespectrumcharacteristicsofmisalignedangleandhorizontalaccelerationcorrectionareanalyzed.Inanairbornegravimetrytest,themisalignedangleofplatformandhorizontalaccelerationcorrectionarecalculated.Theyare5'and3mGal,respectively,whentheflightisstable.
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.
简介:TheliftforcesonhorizontalcylindernearbottomisexperimentallyinvestigatdeatReynolds(Re)intherangelf2500~10000andKeulegan~CARPENTERNUMBERS(kc)intheintervalof5~20,andgapratio(e/D)isfrom(a0)areanalyzdebyusingtheFourieranalysesmethod.ItisfoundthatfoundthatbothCl&a0arethefunctionslftheKcnumber.
简介:Afullsolutionoftwo-dimensionalNavier-Stokesandenergyequationwasconductednumericallytoanalyzethenaturalconvectionofthehorizontalstripwithanadiabaticsubstrate.Themainfeaturesofsuchconvectionare:(i)theleadingandtrailingedgeeffect,(ii)thenon-boundarylayereffect,and(iii)thesideedgeeffect.Theresultsarecomparedwiththeboundarylayertheoryandexprimentaldata.
简介:Themechanismfortransportingliquidfromthebottomofthepipetothetopstilltobeestablishedinthepredictionofthefilmthicknessdistributioninhorizontalannulartwo-phaseflow.Toresolvethisissue,usingfiveparallel-wireconductanceprobes,timerecordsoflocalliquidfilmthicknessatfivecircumferentialpositionswerecollected.Thecharacteristicsofcircumferentialliquidfilmthicknessprofilesanditsvariationwithgasandliquidvelocitieswereobtained.Thebasicfeaturesofprobabilitydistributionfunction,probabilitydensityfunction,auto-correlation,cross-correlationandpowerspectrumdensityfunctionofthedisturbancewavesinannularflowwerestudiedrespectively.Thecharactersticsofcircumferentialprofilesofdisturbancewavesanditsvariationwithgasandliquidvelocitieswerepresented.
简介:Objective:Toinvestigatetheefficacyofquickrepositioningmaneuverforhorizontalsemicircularcanalbenignparoxysmalpositionalvertigo(H-BPPV).Methods:Clinicaldataof67patientswithH-BPPVwhounderwentquickrepositioningmaneuverinourhospitalfromJuly2009toNovember2014wereretrospectivelyanalyzed.Themaneuverinvolvedrotatingthepatientintheaxialplanefor180fromtheinvolvedsidetowardscontralateralsideasquicklyaspossible.Results:Completesymptomresolutionwasachievedin61patients(91.0%)atoneweekandin64patients(95.5%)at3monthspost-treatment.Duringtherepositioningmaneuverprocess,therewerenoobviousuntowardresponsesexcepttransientnauseawithorwithoutvomitinginafewpatients.Conclusion:TheresultsindicatethatthequickrepositioningmaneuverisaneasyandeffectivealternativetreatmentinthemanagementofHBPPV.
简介:Thenumericalinvestigationofregularwavesinteractingwithasubmergedhorizontaltwin-platebreakwaterispresentedinthispaper.Anumericalmodelwithanabsorbingwave-makerisestablishedbasedontheVOFmethod.Thevalidityofthemodelisverifiedbyexperimentalresults.Comparisonsbetweenthenumericalandexperimentalresultsshowthatboththewatersurfaceprofilesandthewave-inducedpressurescanbemodeledaccurately.Wavedeformationoverthebreakwater,waterparticlevelocitiesaroundthebreakwater,andthewave-inducedpressuresonthestructurearenumericallyinvestigated.Thepressureamplitudesofthefundamentalandsecondharmonicsonthemodelsurfaceareexaminedinvariouswaterdepths.Thecomputedandexperimentalresultshaverevealedthatthehigherfrequencycomponentsaregeneratedattheonshoresideofthebreakwater.Furthermore,thecomputedresultsdemonstrateacirculatingflowformedattheonshoresideofthebreakwater.
简介:Throughmechanicalanalysis,animprovedhydraulicmodelforannularcuttingstransportwithfoamwasestablishedforhorizontaldrilling.Basedonthetwocriticalinclinationangles,theentirewellwasdividedintothreesegments.TheBagnoldstress,generalizedpowerlawrheologicalmodelandmodifiedhinderedparticlesettlingvelocityinfoamfluidwereadoptedinthemodeltoimprovethesimulationaccuracy.Theproposedmodelallowsmoreprecisepredictionofcuttingstransportpropertyinthewholerangeofwellinclinationangle.Modelperformancewasexaminedviacasestudyandexperimentaldata.Simulationresultsgivenbythepropulsioniterationandtrial-and-errormethodagreewellwithin-situhorizontalwelldrillingpracticeforthecasestudy,andthecomparisonbetweenthemodelpredictionandCapo’sexperimentaldatashowssatisfactoryagreement.