Kinetic theory of partially ionized reactive gas mixtures

We investigate partially ionized reactive gas mixtures in the presence of electric and magnetic fields. Our starting point is a generalized Boltzmann equation with a chemical source term valid for arbitrary reaction mechanism. We study the Enskog expansion and obtain macroscopic equations in the zeroth- and first-order regimes, together with transport fluxes and transport coefficients. New bracket expressions are obtained for perpendicular/transverse diffusion, thermal diffusion and thermal conductivity coefficients as well as shear viscosity coefficients. A new definition of thermal diffusion ratios—consistent with the zero magnetic fields limit—is introduced. Positivity properties of multicomponent diffusion matrices are investigated and macroscopic entropy production is shown to be positive. The mathematical structure of the transport linear systems that are to be solved in order to evaluate transport coefficients is discussed. In particular, all transport coefficients are expressed as convergent series. These series yield by truncation accurate approximated coefficients relevant to computational models.