简介：Therearemanyphenomenathatgeneratepolygonaltessellationsonsurfacesof3Dobjects.Oneinterestingexampleisthejackfruit,amultiplefruitfoundinthetropics.Arecentstudyfoundthebest-fitsphericalVoronoidiagramfromaphotoofjackfruitskin,buttheoptimizationwasrelativetotheradiusofthesphereandtheheightofthespikes.Inthisstudy,weproposeamethodforadjustingthepositionofthecenterofthesphereinadditiontotheseparameters.Experimentswereconductedusingbothidealandrealdata.However,convergencewithrealdatahasnotbeenconfirmedduetorelaxationoftheconvergencecondition.

简介：高效率的优点，低SFC(特定的燃料消费)，超离频绕过比率扇涡轮引擎吸引越来越多的注意在现代广告引擎。中间的汽轮机管(ITD)它高连接有低压力的压力汽轮机(HPT)汽轮机(并行口)，由指导流动没有太多损失，从HPT来到并行口在汽轮机的全面表演上有批评影响。因此，掌握设计好攻击的、甚至超级好攻击的ITD的技术变得越来越迫切。更多担心被专注于管。然而，改进汽轮机以便推进，并行口嘴被排列成ITD弄短低压力轴。与如此的设计概念，那块并行口嘴流动地被在上游的管结构容易影响，是明显的，但是相反收到少得多兴趣。在这份报纸，数字方法被用来调查一些ITD的效果与在上游打漩并行口上的片嘴。有一样的九个模型打漩并且嘴片当ITD的长度是唯一的时要换掉的参数，将被讨论。最后，为设计者的几个结论和忠告被总结。在改变管，入口和插头的轴的长度以后，嘴的流动地相应地不同。在另一方面，表面介绍的嘴片(吸和压力)上的砍的压力在各种各样的入口流动下面的单个特征。除了那，像计时的效果在这份报纸被描述，它将贡献大部分到压力损失并且应该被付足够的注意。

简介：ThecomparisonanalysesbetweentwotropicaldepressionsintheSouthChinaSeaarecompletedbynumericalex-perimentswithalimitedareamodeldevelopedinGuangzhouInstituteofTropicalandOceanicMeteorology.Oneofthedepressionsdevelopsandfinallybecomesatyphoonwithin24hoursoftheanalyzingperiod(definedasDVDhereafter),andtheothernot(definedasUNDVD)Theanalysesshowthattheirinitialstructuresoftemperature,humidity,pres-sure.windandstabilityareobviouslydifferentfromeachother.Thereareaverydeepwetlayerandaclearwarm-coredstructureinthemid-lowertroposphereinthedepressionareaintheDVDcase,butwiththewarmcoreintheupperratherthanlowertropospherearidaveryshallowwetlayerinthelowertroposphereinthedepressionareaintheUNDVDcase.Thedevelopingandnon-developingprocessesaresuccessfullysimulatedbythemodel,showingthattheCISKmechanismplaysthemostimportantroleinthedevelopmentofSCSDs(TropicalDepressionsintheSouthChinaSea).SeveralnumericalexperimentsshowthatthestructuresofhumidityandtemperatureinthedepressionareahaveimportanteffectonthedevelopmentofSCSDs.ItisfavourabletothedevelopmentofSCSDswhenaverydeepwetlayerexistsinthemid-lowertroposphereorawarm-coredstructureexistsinthemid-lowertroposphereinsteadofinuppertroposphere,andconversely,itisunfavourabletothedevelopmentofSCSDswhenthewetlayerisveryshallowinthelowertroposphereorthewarm-coredstructureisintheuppertroposphereratherthaninmid-lowertroposphere.Thestructuresofstabilityforeachcasearealsoanalysed,whichshowsevidentdifferencesbetweenthetwocases,withadeeperinstabilitylayerintheDVDcaseandashalloweroneintheUNDVDcase.Finally,thesensitivityofthedevel-opmentoftheSCSDstotheverticalstructuresofhumidityandtemperatureinthedepressionareaisdiscussed.

简介：Thispaperdevelopsanumericalmethodtoinvertmulti-dimensionalLaplacetransforms.Byavariabletransform,Laplacetransformsareconvertedtomulti-dimensionalHansdorffmomentproblemssothatthenumericalsolutioncanbeachieved.Stabilityestimationisalsoobtained.Numericalsimulationsshowtheefficiencyandpracticalityofthemethod.

简介：Tostudythemechanicalpropertiesofthefilm/substratestructure,thefiniteelementcodeABAQUSv6.9-1isadoptedtosimulatethetensilemechanicalbehaviorofthenanoscalethinfilmbondedtoasubstrate.Thebifurcationphenomenonofthestructureunderuniaxialtensionisfound:thesingle-neckdeformation,themultiple-neckdeformationandtheuniformdeformation.Thesubstrateandthefilmareregardedaspower-hardeningmaterialsobeyingtheJ2deformationtheory.Firstly,theinfluenceofmaterialhardeningmatchontensilebifurcationmodeisanalyzedunderperfectlywell-bondedinterfacecondition.Then,theeffectsofinterfacialstiffnessandothersuperficialdefectssurroundingtheimperfectiononbifurcationmodeareinvestigated.Itisconcludedthatunderthewell-bondedinterfacecondition,ifthestressofthesubstrateislargerthanthefilm,thefilmwilluniformlydeformwiththesubstrate;ifthestressofthesubstrateissmallerthanthefilm,thefilmwillformasingleneck,exceptthecasethataweakly-hardeningfilmisbondedtoasteeply-hardeningsubstratewhenmultipleneckscanbeformed.Withthedecreaseofinterfacialstiffness,theuniformdeformationmodecantransformintothemultiple-neckdeformationmode,andfurthertransformintothesingle-neckdeformationmode.Andotherdefectssurroundingtheimperfectioncaninfluencethewavelengthofdeformationandnecknumber.

简介：因为免费表面旋涡吸收的空气在抽的系统上导致噪音，颤动，和成穴腐蚀，免费表面旋涡控制在一个泵池系统是重要的。在这研究，在泵吸入的免费表面旋涡和空气吸收的变化被部分(VOF)方法的体积与稳定的多相的流动模型一起调查了以便确切代表免费表面旋涡的行为。同类的免费表面模型被用来使用空气和水的相互作用。结果证明由免费表面旋涡运动的空气吸入能用空气体积部分的iso表面被设想。旋涡用免费表面做空气列到泵吸入。另外，免费表面旋涡能被安装窗帘墙控制，这被发现。

简介：ThevalueofaEuropeanoptionsatisfiestheBlack-Scholesequationwithappropriatelyspecifiedfinalandboundaryconditions.Wetransformtheproblemtoaninitialboundaryvalueproblemindimensionlessform.Therearetwoparametersinthecoefficientsoftheresultinglinearparabolicpartialdifferentialequation.Forarangeofvaluesoftheseparameters,thesolutionoftheproblemhasaboundaryoraninitiallayer.Theinitialfunctionhasadiscontinuityinthefirst-orderderivative,whichleadstotheappearanceofaninteriorlayer.Weconstructanalyticallytheasymptoticsolutionoftheequationinafinitedomain.Basedontheasymptoticsolutionwecandeterminethesizeoftheartificialboundarysuchthattherequiredsolutioninafinitedomaininxandatthefinaltimeisnotaffectedbytheboundary.Also,westudycomputationallythebehaviourinthemaximumnormoftheerrorsinnumericalsolutionsincasessuchthatoneoftheparametersvariesfromfinite(orprettylarge)tosmallvalues,whiletheotherparameterisfixedandtakeseitherfinite(orprettylarge)orsmallvalues.Crank-Nicolsonexplicitandimplicitschemesusingcenteredorupwindapproximationstothederivativearestudied.Wepresentnumericalcomputations,whichdetermineexperimentallytheparameter-uniformratesofconvergence.Wenotethatthisrateisratherweak,dueprobablytomixedsourcesoferrorsuchasinitialandboundarylayersandthediscontinuityinthederivativeofthesolution.

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简介：Afixedlink(tunnelandbridge,intotal16km)wasconstructedbetweenSwedenandDenmarkduring1995-2000.Aspartofthework,approximately16milliontonnesofseabedmaterials(limestoneandclaytill)weredredged,andabout0.6milliontonnesofthesewerespilledinthewater.Modellingofthespreadingandsedimentationofthespilledsedimentstookplaceaspartoftheenvironmentalmonitoringoftheconstructionactivities.Inordertoverifytheresultsofthenumericalmodellingofsedimentspreadingandsedimentation,anewmethodwiththepurposeofdistinguishingbetweenthespilledsedimentsandthenaturallyoccurringsedimentswasdeveloped.Becausethespilledsedimentstendtoaccumulateattheseabedinareaswithnaturalsedimentsofthesamesize,itisdifficulttoseparatethesebasedpurelyonthephysicalproperties.Thenewmethodisbasedonthegeo-chemicaldifferencesbetweenthenaturalsedimentintheareaandthespill.ThebasicpropertiesusedarethehighercontentofcalciumcarbonatematerialinthespillascomparedtothenaturalsedimentsandthehigherCa/Srratiointhespillcomparedtoshellfragmentsdominatingthenaturalcalciumcarbonatedepositioninthearea.ThereasonforthesedifferencesisthatcarbonatederivedfromrecentshelldebriscanbediscriminatedfromDanienlimestone,whichisthematerialinwhichthemajorityofthedredgingtookplace,onthebasisoftheCa/Srratiobeing488inDanienLimestoneand237inshelldebris.Thegeochemicalrecognitionoftheoriginofthesedimentsprovedusefulinseparatingthespilledfromthenaturallyoccurringsediments.Withoutthisseparation,validationofthemodellingofaccumulationofspilledsedimentswouldnothavebeenpossible.Themethodhasgeneralvalidityandcanbeusedinmanysituationswheretheoriginoragivensedimentissought.

简介：Fluid-particleinteractionunderpinsimportantbehaviorofgranularmedia.Particle-scalesimulationmayhelptoprovidekeymicroscopicinformationgoverningtheinteractionandofferbetterunderstandingofgranularmediaasawhole.Thispaperpresentsacoupledcomputationalfluiddynamicsanddiscreteelementmethod(CFD-DEM)approachforthispurpose.ThegranularparticlesystemismodeledbyDEM,whilethefluidflowissimulatedbysolvingthelocallyaveragedNavier-StokesequationwithCFD.ThecouplingisconsideredbyexchangingsuchinteractionforcesasdragforceandbuoyancyforcebetweentheDEMandCFD.Theapproachisbenchmarkedbytwoclassicgeomechanicsproblemsforwhichanalyticalsolutionsareavailable,andisfurtherappliedtothepredictionofsandheapformationinwaterthroughhopperflow.Itisdemonstratedthatthekeycharacteristicofgranularmaterialsinteractingwithporewatercanbesuccessfullycapturedbytheproposedmethod.

简介：此法是由0到10共11个数字组成，病人用0至10这11个数字描述疼痛强度，数字越大疼痛程度越来越严重。0无痛，1～3轻度疼痛（疼痛不影响睡眠），4—6中度疼痛，7—9重度疼痛（不能入睡或者睡眠中痛醒），10剧痛。应该询问患者疼痛的程度，作出标记，或者让患者自己画出一个最能代表自身疼痛程度的数字。

简介：天气研究预报模型(WRF)与高分辨率和NCEP1?设置了???ㄠ???????????????????????????è

简介：Thepresentsimulationinvestigatesthemultiphasecavitatingflowaroundanunderwaterprojectile.BasedontheHomogeneousEquilibriumFlowassumption,amixturemodelisappliedtosimulatethemultiphasecavitatingflowincludingventilatedcavitationcausedbyairinjectionaswellasnaturalcavitationthatformsinaregionwherethepressureofliquidfallsbelowitsvaporpressure.Thetransportequationcavitatingmodelisapplied.ThecalculationsareexecutedbasedonasuiteofCFDcode.Thehyd...

简介：Anumericalstudywasconductedforthefullydevelopedlaminarflowinrotatingcurvedellipticalpipe.Duetotherotation,theCoriolisforcecanalsocontributetothesecondaryflow.Theinteractionofrotationandcurvaturecomplicatestheflowcharacteristics.Theboundary-fittedcoordinatewasadoptedtostudytheflowcharacteristicintherotatingsystems.Theeffectsofrotationontheflowtransitionwerestudiedindetail.Thegenerationandmergenceofvorticesinrotatingcurvedellipticalpipeswerealsocapturedforthefirsttime.Thesimulationresultsshowthattheflowforthecaseoflargeaspectratioofthecross-sectionismorelikelytobeunstablethanthatforsmallerone.

简介：Thispaperpresentsanumericalanalysisofgas-solidseparationinarotationaltubeseparator.Thisseparatorwhichcollectsfineparticlesfromgasinlaminarflowiseffectiveforfineparticleseparation.TheseparationefficiencyandcriticalparticlediameteroftheseparatorweresimulatedusingCFDpackage(FLUENT6.0).Thesimulationshowedthatseparationefficiencycanbesignificantlydecreasedduetothepresenceofturbulence.ThesimulationalsoshowedthattheSaffmanliftforcehaslittleeffectontheefficiencyofthisseparator.Thecriticalparticlediameterofthistubeseparatorwasalsocalculatedtheoretically.Someexperimentaldatawereprovidedtovalidatethesimulationresults.Comparisonbetweenexperimentalresultsandsimulationpredictionsonseparationefficiencyshowedsatisfactoryagreement.

简介：Two-dimensionalhydrodynamicsimulationfortheYangtzeEstuaryisperformedbyusingtheDelft3Dmodeladoptingtheshallowwaterequationsandthefinitevolumemethodonacurvilinearbody-fittedgrid.Themodeliscalibratedandvalidatedusingavailabletidaldataandfieldmeasurements.Thevelocityvectorfields,thetidallevels,thetrajectoriesofdroguesandthefarfieldsewagedilutionfromtheexistingandproposedoutfallsarestudiedforthespring/neaptideandthedry/wetseason.Theresultsshowthatthetidalcurrentsandtherunoffflowareabletodiluteanddispersethesewagefromtheoutfallstotheoutersea.ThesewagedilutioncontoursundervarioushydrodynamicconditionsindicatethatthedischargedeffluentatpresenthaverelativelyminorimpactonthewaterenvironmentoftheYangtzeEstuary;whereastheplannedsewageplanwouldsignificantlydeterioratethewaterqualityoftheestuaryintheabsenceofanytreatment,especiallyduringtheneaptideofdryseason.ThedroguetrackingshowsthattheeffluentfromthefourouffallswillbetransporteddownstreamtotheHangzhouBay.Astudyonthepollutionduetotheprojectandtheself-purificationcapacityofHangzhouBayisproposedinadditiontothatoftheYangtzeEstuary.

简介：TheGoda'smethodofseparatingthefrequencyspectrumoftheunidirectionalincidentandreflectedwavesisimproved.Theproposedmethodcanbeappliedtotheseparationofobliqueincidentandreflectedwavesandthetwowavegaugescanbearrangedinanarbitraryangleinfrontofastructure.Whentheprojecteddistanceofthetwoprobesontheincidentwavedirectionisthemultipleofthehalflengthoftheincidentwaves,thesingularproblemwillemergebyusingthemethod.Itisadvisedthatwhentheprojecteddistanceofthetwomeasuredpointsontheincidentwavedirectionis0.05～0.45timesthewavelengthofpeakfrequencywave,goodresultscanbeobtained.Thesimulatedresultantwavesareseparatedbythemethodofnumericalsimulationandtheseparatedwavespectraarebasicallycorrespondingtothetargetspectrainput.Thewavetrainscalculatedbytheseparatedincidentandreflectedwavefrequencyspectrumareapproximatedtotheinputwavetrainsandthereflectedcoefficientcanbederivedcorrectly.Therefore,themethodproposedinthispaperisreliable.

简介：基于DCA机翼的一个原型和10%弦的轴的排水量重叠，七种正切的排水量被拿与数字方法在双人脚踏车串联模仿流动条件与高效选择更好的几何学。有正切的排水量b/t=0.83的配置将比其它获得更好的流动性能。在这个基础上，有正切的排水量b/t=0.67的二种配置并且0.83在几种配置之中被选择由使用TR-PIV系统即刻地捕获流动速度拿进试验性的调查。有b/t=0.83的配置被观察更好的流动地表演比b/t=0.67。它在差距地区的注射流动强壮得多，弄醒前面的地区区域并且高耸片更小，溪流流动是改进的更多。它证明在试验性的调查的流动表演相当在数字结果预言的一样的趋势。

简介：Ageneralnumericalmethodispresentedforcalculatingsteadythree-dimensionalandtwo-phaseturbulentreactiveflowswithanonstaggeredbody-fittedcoordinatesysteminanannulargasturbinecombustorwiththedumpdiffuser.Themodifiedtwo-equationmodelandtheEDCturbulentcombustionmodelareusedforthegasphase.TheliquidphaseequationsaresolvedinaLagrangianframeofreferencebyPSICalgorithm.Theeffectofdifferentvelocityprofilesattheentryoftheprediffuseroncombustorflowcharacteristicsiscalculated.

简介：Inthispaper,anewhybridcontroltechnique,basedonacombinationofbase-isolationandsemi-activevariablestiffness/dampinginasuperstructure,ispresented.Toillustratetheefficiencyoftheproposedcontrolsystem,modeltestsonamini-electromagneticshakingtableandanumericalsimulationwereperformed.Thetestandnumericalcalculationresultsindicatethatthisnewhybridcontrolmodewithadditionaldampingandsmalleradditionalstiffnesscanachieveabettercontrolefficiency.