Classical Mechanics Calculations of the Transport Properties of Gaseous Mixtures with Internal Degrees of Freedom

Following the theory of thermodynamics of irreversible processes for mixtures of reacting gases, expressions are derived for the diffusion and thermal diffusion coefficients of gases with internal degrees of freedom, in the two limiting cases of infinitely slow, and of infinitely rapid exchange between translational and internal energies. Classical mechanics trajectory calculations provide the necessary total inelastic cross sections for the transport collision integrals. For molecules with an asymmetric mass distribution the nonspherical interaction is treated with a realistic rotating potential field. Application to the systems D2‐HD and D2‐HT yield excellent agreement with experimental diffusion data. Thermal diffusion factors are extremely sensitive to nonspherical interactions through a correction term analogous with the Eucken correction in thermal conductivity. Derivations from the kinetic theory of Wang Chang, Uhlenbeck, and de Boer give the same correction term. At low temperatures the agreement ...