Kinetic theory for the volume viscosity in binary mixtures of polyatomic and noble gases

Abstract

A kinetic expression for the volume viscosity of binary mixtures of polyatomic and noble gases in terms of effective collision cross sections is derived within the framework of first order Chapman-Enskog theory using an inverse operator method. It is shown that the rotational relaxation rate, which is directly related to the volume viscosity, depends linearly on the composition of the mixture if it is assumed that coupling to higher order polynomials in internal and translational energy may be neglected. This result agrees with earlier predictions.