Thermodynamics of one side of a face for a gas mixture: the frozen ratio of specific heats and the energy offset, with rho E = p / (gamma - 1) + rho e0 + rho |u|^2 / 2 (e0 = 0 for a calorically perfect gas), and the pair the wave-speed estimates use: the same but in double flux, where both fluxes of a face estimate the waves with each side's own cell's, so that their mass fluxes agree at contacts.
More...
Thermodynamics of one side of a face for a gas mixture: the frozen ratio of specific heats and the energy offset, with rho E = p / (gamma - 1) + rho e0 + rho |u|^2 / 2 (e0 = 0 for a calorically perfect gas), and the pair the wave-speed estimates use: the same but in double flux, where both fluxes of a face estimate the waves with each side's own cell's, so that their mass fluxes agree at contacts.