Chapman–Enskog solution for diffusion: Pidduck’s equation for arbitrary mass ratio

Abstract

In several studies of rarefied gas dynamics and particle transport, not only the diffusion coefficient, but also a detailed description of the Chapman–Enskog solution for diffusion is required. The case of diffusion of a trace species in a background gas is considered for arbitrary molecular mass ratio, and accurate results are reported for the Chapman–Enskog solution obtained by solving numerically an integral equation of Pidduck.