简介：Mostcurrentcomputationsoftrubulentflowswithsecond-momentclosureadoptthediffusionmo-delswhichneglecttheeffectofpressure-velocitycorrelation.lnthepresentpapertheimportanceofthiscorrelationeffectiselucidatedtheneglectofthiseffectaccountsforsomemajordefectsinthewideapplicationofthese-cond-momentclosures.Throughtherelationbetweenand,establishedbyLumley,weproposehereanewturbulencediffusionmodelwhichtakesintoconsiderationthepressureeffect.Applicationsofthisnewmodelinthecomputationofshearlessturbulencemixinglayerandplane-andround-jetflowsshowthatthespreadingrateoftheseflowscanbesatisfactorilycaptured.

简介：在1990年代初执行的以前的研究推测了主要可压缩的效果能与速度变化的dilatational效果被联系。后来，主要压缩的可能性效果由于减少的压力变化来自减少的压力紧张术语，这被显示出。尽管可压缩的骚乱的更好的理解通常与增加的DNS和试验性的研究努力被完成，仍然在这些最近的调查结果之中有一些差异。如果可压缩的效果与狂暴的马赫数字有关，DNS和试验性的数据的分析建议一些差异是明显的，Mt。从可压缩的流动的二个班的比较，同质砍流动并且不同类砍流动(混合的层)，我们发现两个班上的压缩的可能性的效果砍流动能在相应于狂暴的马赫数字的三个区域的三个范畴被描绘：low-Mt,moderate-Mt并且high-Mt区域。在这三个区域，狂暴的混合层厚度的生长率上的压缩的可能性的效果是相当不同的。减少的压力紧张效果的一条简单途径不能必然减少混合层生长率，并且可以甚至处于生长率引起增加。现在的工作通过Mt在流动上说明压缩的可能性效果。模型成功地被用于可压缩的混合层。

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简介：TheresultsofplaneturbulentwakegivenbyChouPeiyuanareconsideredasthefirstorderap-proximationandputintotheequationsofturbulentfluctuation.Theequationsaresolvednumericallywithintherangeofmicro-scalebymeansofspectrummethod.Thedouble,tripleandquadruplefluctuatingvelocitycorrelationsareobtainedbycomputation.Theyareingoodagreementwithexperimentalresults.

简介：计算液体动力学(CFD)广泛地被用来学习gassolid使液化的水动力学；然而，它在liquidsolid使液化的应用是相对稀罕的。在这研究，liquidsolid的CFD模拟使流体化床被执行，集中于效果在liquidsolid使液化的水动力学上拖关联和增加的集体力量。拖关联，这被显示出模拟结果和关联上的重要效果由Beetstra等求婚了。(2007)与试验性的数据给最好的协议。我们进一步证明增加的集体力量确实在liquidsolid使液化的CFD模拟起一个重要作用，不应该因此在CFD模拟被忽略。

简介：Numericalsimulationofgas-solidflowinatwo-dimensionalfluidizedbedwithaninclinedjetwasperformed.Thenumericalmodelisbasedonthetwo-fluidmodelofgasandsolidsphaseinwhichthesolidsconstitutiveequationsarebasedonthekinetictheoryofgranularflow.TheimprovedICEalgorithm,whichcanbeusedforbothlowandhigh-velocityfluidflow,wereusedtosolvethemodelequations.Themechanismofjetformationwasanalyzedusingbothnumericalsimulationsandexperiments.Theemergenceandmovementofgasbubbleswerecapturednumericallyandexperimentally.Theinfluencesofjetvelocity,nozzlediameter,nozzleinclinationandjetpositiononjetpenetrationlengthwereobtained.Asemi-empiricalexpressionwasderivedandtheparameterswerecorrelatedfromexperimentaldata.Thecorrelationequation,whichcanbeeasilyusedtoobtaintheinclinedjetpenetrationlength,wascomparedwithourexperimentaldataandpublishedcorrelationequations.

简介：Thispaperstudiestheinterfacecuringstressesbetweenpolymethylmethacrylate(PMMA)andcompositebymeansofdigitalspecklecorrelationmethod(DSCM).AnewmethodbycombiningDSCMwiththemarkerpointsisdevelopedtomeasuretheinterfacecuringstresses,andthemeasurementprincipleisintroduced.TheinterfacecuringstressesbetweenPMMAandcompositewithdifferentcuringbondingconditionsaremeasuredandanalyzed,thisindicatesthattheresidualstressforfurnaceheatingandfurnacecooling...

简介：Wakestructuresandvortexinducedvibration(VIV)ofaspring-supportedwide-D-sectioncylinderwereexperimentallyinvestigatedusinganX-wire,anovelphase-lockedparticleimagevelocimetry(PIV),andanaccelerationsensoratalowspeedwindtunnel.Comparedwiththefixedcase,the2P(twopair)vortexmodeasdefinedbyGovardhanandWilliamson(2000)ratherthanS(singlevortex)modeexistsinthewake.Thevelocitydeficitbehindthecylinderismuchlargerthanthatoffixedcase.Themeandragcoefficientincreasesfrom1.42forthefixedcaseto1.64forthevibratingcase.TheReynoldsstresspresentsevendistributionandsmallwithincreaseddistanceofX/D=-2toX/D=-10.Thepowerspectradensitybasedonacceleratorandhotwiredatapresentsahighlightidentical.Itshowsthatafterastronginteractionthecylindervibrationandthevortexsheddingcometoastablestate.Thevortexsheddingistotallylockedonandcontrolledbythecylindervibration.

简介：Amodelisproposedtocorrelatethecrackgrowthrateandstressratiocontainingveryhighcyclefatigueregime.Themodelisverifiedbytheexperimentaldatainliterature.Thenaformulaisderivedfortheeffectofmeanstressonfatiguestrength,anditisusedtoestimatethefatiguestrengthofabearingsteelinveryhighcyclefatigueregimeatdifferentstressratios.TheestimatedresultsarealsocomparedwiththosebyGoodmanformula.

简介：Polymerbondedexplosives(PBXs)arehighlyparticle-filledcompositematerials.ThispaperexperimentallystudiesthetensiledeformationandfracturebehaviorofaPBXsimulationbyusingthesemi-circularbending(SCB)test.Thedeformationandfractureprocessofapre-notchedSCBsamplewitharandomspecklepatternisrecordedbyachargecoupleddevicecamera.Thedisplacementandstrainfieldsontheobservedsurfaceduringtheloadingprocessareobtainedbyusingthedigitalimagecorrelationmethod....

简介：Globallook-uptablestrategyproposedrecentlyhasbeenproventobeanefficientmethodtoacceleratetheinterpolation,whichisthemosttime-consumingpartintheiterativesub-pixeldigitalimagecorrelation(DIC)algorithms.Inthispaper,agloballook-uptablestrategywithcubicB-splineinterpolationisdevelopedfortheDICmethodbasedontheinversecompositionalGauss–Newton(IC-GN)algorithm.Theperformanceofthisstrategy,includingaccuracy,precision,andcomputationefficiency,isevaluatedthroughatheoreticalandexperimentalstudy,usingtheonewithwidelyemployedbicubicinterpolationasabenchmark.Thegloballook-uptablestrategywithcubicB-splineinterpolationimprovessignificantlytheaccuracyoftheIC-GNalgorithm-basedDICmethodcomparedwiththeoneusingthebicubicinterpolation,atatrivialpriceofcomputationefficiency.

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