学科分类
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1 个结果
  • 简介:Theabsenceofsub-gridscale(SGS)motionsleadstosevereerrorsinparticlepairdynamics,whichrepresentsagreatchallengetothelargeeddysimulationofparticle-ladenturbulentflow.Inordertoaddressthisissue,datafromdirectnumericalsimulation(DNS)ofhomogenousisotropicturbulencecoupledwithLagrangianparticletrackingareusedasabenchmarktoevaluatethecorrespondingresultsoffilteredDNS(FDNS).ItisfoundthatthefilteringprocessinFDNSwillleadtoanonmonotonicvariationoftheparticlecollisionstatistics,includingradialdistributionfunction,radialrelativevelocity,andthecollisionkernel.Thepeakofradialdistributionfunctionshiftstothelarge-inertiaregionduetothelackofSGSmotions,andtheanalysisofthelocalflowstructurecharacteristicvariableatparticlepositionindicatesthatthemosteffectiveinteractionscalebetweenparticlesandfluideddiesisincreasedinFDNS.Moreover,thisscaleshiftinghasanobviouseffectontheodd-ordermomentsoftheprobabilitydensityfunctionofradialrelativevelocity,i.e.theskewness,whichexhibitsastrongcorrelationtothevarianceofradialdistributionfunctioninFDNS.Asawhole,theradialdistributionfunction,togetherwithradialrelativevelocity,cancompensatetheSGSeffectsforthecollisionkernelinFDNSwhentheStokesnumberbasedontheKolmogorovtimescaleisgreaterthan3.0.However,itstillleavesconsiderableerrorsforStk<3.0.

  • 标签: Particle-laden TURBULENCE HOMOGENOUS ISOTROPIC TURBULENCE Large