SIMPLE APPROXIMATION FOR THERMAL-DIFFUSION IN GAS-MIXTURES

A new simple approximation is proposed for thermal diffusion in gas mi xtures. This approximation is based upon a recently described hydrodyn amic theory of multicomponent diffusion [1]. It provides an approximat e expression for the thermal diffusion coefficients in terms of the bi nary diffusion coefficients for each pair of components in the mixture . The new approximation supersedes a previous approximation given in [ 1], which was too crude to be useful.