Fluid-dynamic model equations for a gas with slow reversible bimolecular reactions

The dispersion relation and shock structure of a gas mixture undergoing a bimolecular chemical reaction are studied by means of a hydrodynamic model deduced from the relevant kinetic equations. Qualitative changes in the solution, in particular loss of smoothness, for varying parameters (including Mach number and strength of the chemical reaction rate) are investigated, and numerical results are presented. In the limits of vanishing or diverging reactive relaxation times the “equilibrium” and “frozen” thermodynamical situations are recovered.