简介:Withthedevelopmentofhigh-resolutionandmulti-scaleunifiednumericalmodel,someoftechniquesaboutnon-hydrostaticmeso-scalenumericalweatherpredictionareaddressed.Theimpactoftheverticalcoordinatesystemisoneofthem.Inthispaper,basedonaWRF(WeatherResearchandForecast)model,theimpactonthecalculationofverticalvelocitywasstudiedwithdifferentverticalcoordinates.Thesimulationresultsshowedthatthecalculationofverticalvelocityissensitivetoverticalcoordinates.Itisespeciallymoreevidentwhentheresolutionincreased.Duetothecloserelationshipsbetweenverticalvelocityandprecipitation,thedifferenceofverticalvelocityinevitablyinfluencesmodel'sdescriptionofprecipitation.Anidealexperimentexhibitsthatpressuregradientforcecomputationsinthepressureterrain-followingcoordinatearesensitivetosurfacepressure.
简介:Densitystratifiedflowwithboththeverticaltemperaturegradientandtheverti-calsalinitygradientissimulatednumerically,inwhichturbulenttermsarecalculatedbyasim-plifiedturbulencestress/fluxalgebraicmodel.Thefeatureofstratificationandturbulenceisde-scribedcorrectlybythemodel.Thecomputationalresultsagreewellwiththeexperimentaldata.However,thek-eturbulencemodelisnotsosuccessful.
简介:Thepresentworkprovidesanovelmethodforcalculatingverticalvelocitybasedoncontinuityequationsinapressurecoordinatesystem.Themethodovercomesthedisadvantageofaccumulationofcalculatingerrorsofhorizontaldivergenceincurrentkinematicsmethodsduringtheintegrationforcalculatingverticalvelocity,andconsequentlyavoidsitssubsequentcorrection.Inaddition,throughmodificationsofthecontinuityequations,itshowsthatthevorticityoftheverticalshearvector(VVSV)isproportionalto-ω,theverticalvelocityinpcoordinates.Furthermore,ifthechangeofωinthehorizontaldirectionisneglected,thevorticityofthehorizontalvorticityvectorisproportionalto-ω.Whenωisunderafluctuatingstateintheverticaldirection,theupdraftoccurswhenthevectorofhorizontalvorticityrotatescounterclockwise;thedowndraftoccurswhenrotatingclockwise.ThevalidationresultindicatesthatthepresentmethodisgenerallybetterthantheverticalvelocitycalculatedbytheωequationusingthewetQ-vectordivergenceasaforcingterm,andtheverticalvelocitycalculatedbyutilizingthekinematicsmethodisfollowedbytheO’Brienmethodforcorrection.Theplus-minussignoftheverticalvelocityobtainedwiththismethodisnotcorrelatedwiththeintensityofdBZ,buttheabsoluteerrorincreaseswhendBZis>=40.Thismethoddemonstratesthatitisagoodreflectionofthedirectionoftheverticalvelocity.
简介:Inthispaper,theprincipleofmirrorimageisusedtotransformtheproblemofwavediffractionfromacircularcylinderinfrontoforthogonalverticalwallsintotheproblemofdiffractionoffoursymmetricincidentwavesfromfoursymmetricallyarrangedcircularcylinders,andthentheeigenfunctionexpansionofvelocitypotentialandGrafsadditiontheoremareusedtogivetheanalyticalsolutiontothewavediffractionproblem.Therelationofthetotalwaveforceoncylindertothedistancebetweenthecylinderandorthogonalverticalwallsandtheincidenceangleofwaveisalsostudiedbynumericalcomputation.
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简介:Regularandirregularwaveforcesactingonverticalwallsarestudiedbyapreviouslydevelopednumericalmodel.Thecomputedwaveforcesarecomparedwiththeavailableexperimentaldatatoverifythenumericalmodel,andsatisfactoryagreementsareobtained.Thevariationofwaveforceswithincidentanglesandtheshapeofsimultaneouspressuredistributionareinvestigated,andthecomparisonsbetweennumericalresultsandGoda'spredictionsarealsocarriedout.Itisconcludedthatthemaximumwaveforcesactingontheunitlengthofverticalwallisofteninducedbytheobliquelyincidentwavesinsteadofnormallyincidentwaves,whileGoda'sformulamaybeinapplicableforobliquewaveincidence.Theshapeofsimultaneouspressuredistributionisnotsignificantlyinfluencedbyincidentangles,anditcanbefavorablypredictedbyGoda'sformula.WhenregularwaveheightsaretakenasthesameasirregularwaveheightH1%,theirregularwaveforcesPh,1%areslightlylargerthanregularwaveforcesinmostcases.
简介:Basedonthe2ndordercnoidalwavetheory,thecharactersofshallowwaterstandingwavesandtheiractiononverticalwallsarestudiedinthispaper.Thetheoreticalexpressionsofthewavesurfaceelevationinfrontofandthewavepressureontheverticalwallareobtained.Inordertoverifythetheoreticalresults,modeltestsweremadeintheStateKeyLaboratoryofCoastalandOffshoreEngineeringatDUT.Forthewavesurfaceelevationinfrontofthewallandthewaveforcesonthewallatthemomentwhenthewavesurfaceatthewallsurfacegoesdowntothebottomofthewavetrough,thecalculatedresultscoincidequitewellwiththeexperimentalresults.Forthewaveforcesonthewallatthemomentwhenthewavesurfaceatthewallsurfacegoesuptothetopofthewavecrest,thetheoreticalexpressionsaremodifiedbytheexperimentalresults.Fortheconvenienceofpracticaluse,calculationsaremadeforthewaveconditionswhichusuallyoccurinengineringpracticebyuseoftheinves
简介:Likevaluechainandsupplychain,“industrialchain”becomesthefocusofattention.Theimplicationof“industrialchain”hasgainedalargerangeofextension.Itnotonlyexpressestheindustrial“chain”structureandrelationshipof“backandforward”inorderor“upanddown”indirection,butalsoitrepresentsaclusteroflargescaleoffirmsinanareaorcolony.Itisanetwork,oracommunity.Consequently,weconcludethat“industrialchain”isasynthesisofindustrialchain,industrialcluster,orindustrialnetwork.Inthisarticle,firstlywewilldistinguishindustrychainfromindustry.Anindustryisthecollectionoffirmsthathavethesameattribute,soanindustrycanbedefinedbyfirmcollectionofcertainattribute.Weindicatethatindustrialchainisakindofverticalandorderlyindustriallink.Itisdefinedaccordingtoaseriesofspecificproductorservicecreated.Secondlyweanalyzetheverticalorderlydefiinitionprocessfromtheaspectsofsocialdivisionoflaborandrequirementdivision,self-organizationsystem,andvalueanalysis.Non-symmetryanddependingonsystemorcommunityoflargescaleofindustrialunitsleadtoentireindustryto“orderly”structure.Ontheotherhand,thedraughtofdiversityandcomplexityofrequirementsimultaneouslyleadtoentireindustrytobemore“orderly”.Alongwithprocessesofself-organization,industrialwillappi'oachthestateofmoreorderlyandsteady,andconstantlymakeindustrialchainupgrade.Eachfirmorunit,whowillgainthevalue,hastoestablishchannelsofvalue,whichwecalled“industrialvaluechain”.Lastly,wediscusstheconsequenceofverticalandorderlydefinition,whichisexhibitedbyacertainrelationshipbody.Thetypicalformsofindustrialchainincludeindustrialcluster,strategyallianceandverticalintegrationetc.
简介:在那里存在,这被证明了在垂直的热之间的生气联合由使用线性热力学的狂暴的运输和垂直速度。这结果断言热的垂直部件狂暴的运输流动由垂直潜在的温度梯度的运输和垂直速度的联合运输组成。在这篇论文,垂直的热上的垂直速度的联合效果狂暴的交通被从大气的边界层使用观察数据决定联合系数的十字验证,并且狂暴的交通的一系列重要性质外面被打开。这些性质显示生气联合系数是尺寸的对数功能不太垂直的速度和尺寸更少高度,并且不仅与磨擦速度u*,有关而且到联合粗糙高度zW0和联合温度T垂直速度的W0。另外,仅仅当垂直速度大小遵循限制|W/u*时,功能关系建议那|≠1,并且在水平z然后,垂直速度导致生气联合的W0,垂直的热上的效果狂暴的运输流动。生气联合理论和试验性的结果提供挑战给传统的狂暴的K闭合理论和Monin-Obukhov类似理论。
简介:Discussionsarecarriedoutontheverticaldiscretizationofcurrentatmosphericmodels.Itispointedoutthatthereexistproblemsintheintegrationofthehydrostaticequationandthecomputationofverticaladvection,verticaldiffusionandsoon.Thensomepossiblewaysforsolvingoralleviatingthemaresuggested.Finally,thechoiceofverticalcoordinateandbasisfunctionsisdiscussed.
简介:切开技术的一时间对许多免费表面海洋模型普通。在内部、外部的模式的方程的不同截断错误要求数字调整保证算法正确地满足连续性方程并且保存tracers数量。princeton海洋模型(POM)使用了在每个内部时间步骤以外部速度调整内部速度的垂直平均数的一个简单方法。然而,由于Asselin时间过滤器,方法采用了阻止数字不稳定性,在POM使用的速度调整的方法能不再在内部模式保证连续性方程的满足,不过,一个特殊处理被用来与外部模式的联系内部模式的表面举起。错误被证明是在Asselin过滤器的系数的一个秒顺序术语。在数字模型的这个错误的一影响是在海地板的运动边界条件的失败。由一个地区性的实验和一个伪全球的实验,这个错误的大小被评估,并且这个错误的几敏感测试被执行。这个错误的特征被分析,二个其他的算法被建议减少错误。
简介:Thispaperfirstdevelopstheapproachestodeterminethegeopotentialofthelocalmeansealevel,andtheninvestigatestheoffsetofthe1985verticaldatumsurfacedefinedbythemeansealevelofYellowSeaattheDagangTideGaugeinQingdaocityusingthedevelopedapproachesandGPS/levelingdata.Itshowsthatthegeopotentialofthelocalmeansealevelatthetidegaugeisequalto62636853.5±0.2m2*s-2andthatthe1985verticaldatumsurfaceis24.6±5.4cmabovethegeoidrealizedbythegeopotentialW0=62636856.0±0.5m2*s-2.
简介:Averticalantennaembeddedinearthwithconductivecoatinghasbeeninvesti-gatedbyemployingthemethodofintegralequation.ThistopicisavailabletoEM-MWD(Elec-tromagneticMeasurement-While-Drilling)system,whichisanewrealtimesystemfordrillingmeasurement.Undertheconditionthatthewavenumberoftheearthismuchlargerthanthatoftheair,acurrentintegralequationhasbeenderived.Afterthecurrentdistributionhavingbeendetermined,theelectricfieldstrengthontheearthsurfacehasbeenpredictedanditsdependencesontheoperatingfrequencyandthedepthofthewellhavebeendiscussedaswell.
简介:Insteady,solid-liquidtwo-phaseturbulentflows,thereexisttwotypicalpatternsoftheverticaldistributionofparticleconcentration.ThepatternIshowsamaximumconcentrationatanelevationabovethebed.ThepatternIIshowsanincreaseoftheparticleconcentrationdownwardoverthewholevertical,withthemaximumatthebed.MostofthetheoriesonparticleconcentrationdistributionhavebeendonewiththepatternII,anditislackofasuccessfultheorycovetingbothofthetwopatterns.Thispaperreviewstheparticledistributiontheories,includingthediffusiontheory,themixturetheory,theenergytheory,thesimilaritytheory,thestochastictheoryandthekinetictheory.Thekinetictheoryisalsoappliedtodescribetheverticaldistributionofparticleconcentrationinbothdiluteanddenseflows.
简介:Thereexistthreetypesofconvolutionformulaefortheefficientevaluationofgravityfieldconvolutionintegrals,i.e.,theplanar2Dconvolution,thespherical2Dconvolutionandthespherical1Dconvolution.Thelargestdrawbackofboththeplanarandthespherical2DFFTmethodsisthat,duetotheapproximationsinthekernelfunction,onlyinexactresultscanbeachieved.Apparently,thereasonisthemeridianconvergenceathigherlatitudes.Asthemeridiansconverge,theΔφ,Δλblocksdonotformarectangulargrid,asisassumedin2DFFTmethods.Itshouldbepointedoutthatthemeridianconvergencenotonlyleadstoanapproximationerrorinthekernelfunction,butalsocausesanapproximationerrorduringtheimplementationof2DFFTincomputer.Inordertomeettheincreasingneedforprecisedeterminationoftheverticaldeflections,thispaperderivesamorepreciseplanar2DFFTformulaforthecomputationoftheverticaldeflections.Afterhavingmadeadetailedcomparisonbetweentheplanarandthespherical2DFFTformulae,wefindoutthemainsourceoferrorscausingthelossinaccuracybyapplyingtheconventionalspherical2DFFTmethod.Andthen,amodifiedspherical2DFFTformulaforthecomputationoftheverticaldeflectionsisdevelopedinthispaper.Aseriesofnumericaltestshavebeencarriedouttoillustratetheimprovementmadeupontheoldspherical2DFFT.Thesecondpartofthispaperistodiscusstheinfluencesofthesphericalharmonicreferencefield,thelimitedcapsize,andthesingularintegralonthecomputationoftheverticaldeflections.TheresultsoftheverticaldeflectionsoverChinabyapplyingthespherical1DFFTformulawithdifferentintegrationradiihavebeencomparedtotheastro-observedverticaldeflectionsintheSouthChinaSeatoobtainasetofoptimumdeflectioncomputationparameters.
简介:Ananalysissolutionofrateequationisderivedforverticalcavitysurface-emittinglasers.BasedontheenhancedspontaneousemissioncausedbyVCSELsandinfluenceofnonradiativerecombination,therelationbetweenoutputpropertiesandstructuralparametersofmulti-quantumwells(MQWs)isobtanined.Itwasfoundthatthecharacteristiccurveofa"thresholdless"laserisstronglynonradiativedepopulation-dependent.Whenthenonradiativedepopulationisnozero,thelight-currentcharacteristicisnotlinearlyevenforanidealclosedmicrocavity.Thelightoutputisincreasedbytheenhancedwellnumberandbythereducedwidth.Inparticular,alowerthresholdcurrentdensityforMQWsstructureintheshortcavityisrealizedbyus,meanwhilethesharpnessofthevariationdependsonspontaneousemissionfactor.
简介:Threetyphoons,Goni,MorakotandEtauwhichweregeneratedinWesternPacificin2009,aresuccessfullysimulatedbytheWRFmodel.Thehorizontalandverticalvorticityandtheirinteractionareanalyzedanddiagnosedbyusingthesimulationresults.Itisshownthattheirresultantvectorshadafixedpatternintheevolutionprocessofthethreetyphoons:Thehorizontalvorticityconvergedtothetropicalcyclone(TC)centerbelow900hPalevel,flowedoutfromitataround900to800hPa,andflowedinbetween800hPaand700hPa.Ifmultiplemaximumwindspeedcentersshowedup,thehorizontalvorticityconvergedtothecenterofthetyphoonbelowthemaximumwindspeedcenteranddivergedfromtheTCcenterabovethemaximumwindspeedcenter.Atlowlevels,thethreetyphoonsinteractedwitheachotherthroughverticalcirculationgeneratedbythevortextube.Thiscirculationwasmainlygeneratedbytheeastwardorwestwardhorizontalvorticityvectors.Cloudsandprecipitationweregeneratedontheascendingbranchoftheverticalcirculation.ThevortextubesoftenflowedtowardthesouthwestoftherightTCfromthenortheastoftheleftTC.Accordingtothefullvorticityequation,thehorizontalvorticityconvertedintotheverticalvorticitynearthemaximumwindspeedcenterbelow850hPalevel,andtheperiodofmostintenseconversionwasconsistentwiththeintensificationperiodofTC,whilethevorticityadvectionwasagainsttheintensification.Theverticalvorticityconvertedintothehorizontalvorticityfrom800hPato600hPa,andthewindspeeddecreasedabovethemaximumwindspeedregionatlowlevels.