Velocity distribution and scaling properties of wall bounded flow

(整期优先)网络出版时间:2010-07-17
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Thescalingandsimilarityofwallboundedturbulentflowwerestudied.Thepropertiesofsuchflowsandtherelationshipbetweenapowerlawandalogarithmictypeofvelocitydistributionwereinvestigated.Basedonthephysicalmechanisminvolved,ourresultsshowthatthepowerlawandthelogarithmicdistributionareonlydifferentformswiththesamehypothesisandholdonlyintheouterflowzone.Thus,auniversalexplanationforvariousempiricalformulaeofvelocitydistributionwasobtained.Manning’sformulawasstudiedtoexplaintheoreticallytheexperientialresultthattheroughnesscoefficientisonlyacomprehensiveparameterofthewholesystemwithoutacorrespondingphysicalfactor.Thephysicalmechanismofthevelocitydistributionofparalleltowallboundedflowwasexplored,theresultsshowthattheparametersintheformulaofvelocitydistributionareindicesofthesystemrespondingtoflowingenvironmentalfactorstorepresentgeneralcaseofboundaryroughnessandtheflowingstate,correspondingphysicalmechanismisvortexmotion.