Kinetic theory of moderately dense gas mixtures: II. Symmetry relations for transport coefficients

Abstract

Proofs of the Onsager relations are given for the Soret and Dufour coefficients and for the coefficients of mutual diffusion in multicomponent gas mixtures, based on the kinetic theory of moderately dense gases, as developed by Bogolubov, Choh, Uhlenbeck, Green and Cohen. Apart from the Onsager relations there exist also symmetry relations between collisional transfer and kinetic contributions to the transport coefficients which have the same origin as the Onsager relations. Since the triple-collision operator used in the kinetic theory of dense gases is not symmetric, the introduction of a symmetric triple-collision operator is an essential ingredient in our proof of the symmetry relations.