Characterizing(Characterizing(表征表征)themoleculartransportof)themoleculartransportofspecies,momentumandenergyinamulticomponentspecies,momentumandenergyinamulticomponentgaseousmixturerequirestheevaluationofdiffusiongaseousmixturerequirestheevaluationofdiffusioncoefficients,viscosities,thermalconductivities,andcoefficients,viscosities,thermalconductivities,andthermaldiffusioncoefficients.thermaldiffusioncoefficients.EvaluatingEvaluatingpurespeciespurespeciespropertiesfollowsstandardpropertiesfollowsstandardkinetictheoryexpression,butforevaluatingkinetictheoryexpression,butforevaluatingmixturemixturepropertiesproperties??12MoleculartransportMoreover,computingthemixturepropertiescanbeMoreover,computingthemixturepropertiescanbeexpensive,itisoftentomakeexpensive,itisoftentomakesimplifyingassumptionssimplifyingassumptionstotoreducethecomputationalcost.reducethecomputationalcost.ThefullThefullmulticomponentformulationmulticomponentformulationhashasadvantagesadvantagesoverthesimplermixtureformulas.overthesimplermixtureformulas.First,isaccuracy.First,isaccuracy.Forsomeapplications,evaluatemixturepropertiesForsomeapplications,evaluatemixturepropertiesfrompurespeciespropertiesviafrompurespeciespropertiesviacertainmixturecertainmixtureaveragingrulesaveragingrules.Howevertheapproximateaveragingrules.Howevertheapproximateaveragingrulesarenotadequate,andarenotadequate,andmulticomponentmethodsmulticomponentmethodsarearenecessary.necessary.Second,applysomeSecond,applysomecorrectionprocedurecorrectionprocedure,the,themulticomponentformulationmulticomponentformulationguaranteesmassguaranteesmassconservationconservationwithoutanycorrectionfactors.withoutanycorrectionfactors.TheonlyrealTheonlyrealdeficiencydeficiencyofthemulticomponentofthemulticomponentformulationisformulationisitscomputationalexpenseitscomputationalexpense..EvaluatingthemulticomponentdiffusioncoefficientsEvaluatingthemulticomponentdiffusioncoefficientsinvolvesinvertingK*Kmatrix.involvesinvertingK*Kmatrix.Evaluatin...
