Classical Theory of Transport Phenomena in Dilute Polyatomic Gases

Abstract

A classical theory of transport phenomena in dilute gases of molecules possessing internal degrees of freedom is presented. It is shown that the existence of inverse collisions is unnecessary for the development of the theory. First-order formal expressions for the coefficients of thermal conductivity, shear viscosity, and bulk viscosity are given. In cases where the molecules make only elastic collisions the expressions found reduce to the well-known Chapman-Enskog results. The treatment is very similar to the semiclassical one of Wang Chang and Uhlenbeck, who treated the internal degrees of freedom quantum-mechanically and could thus use the fact that quantum inverse collisions exist. Their theory reduces to the present one in the classical limit.