Transport Properties of Ionized Monatomic Gases

Expressions are developed with the Chapman‐Enskog‐Burnett method for the third and fourth approximations to the thermal conductivity and the diffusion coefficients, and for the second approximation to the viscosity of multicomponent gas mixtures. Special forms of these expressions are then derived for application to ionized gas mixtures, in particular to the partially ionized gas. Convergence of the approximations is checked by computing the properties of fully ionized hydrogen and of several other mixtures where the molecules interact with inverse‐power repulsive potentials. From the results for hydrogen, it is seen that at least the third approximation should be used for the thermal conductivity and thermal diffusion coefficient, and the second approximation for the electrical conductivity and viscosity of ionized gases. These results contrast with those for un‐ionized gases where one lower level of approximation is generally adequate.