Correction of Conservative Euler Solvers for Gas Mixtures

Conservative Euler solvers for gas mixtures produce numerical errors near contact discontinuities, if the temperature and the ratio of specific heats are not constant there. For mixtures of perfect gases, a simple correction of the total energy per unit volume is proposed to avoid these errors. This is done in a physical way and only the total energy looses some of its conservativity. Numerical simulations of contact discontinuity convection, a shock tube problem, and shock-interface interactions in 1D and 2D yield much more accurate solutions, if the correction is applied. The straightforward extension to 3D is outlined.