An ES-BGK model for diatomic gases with correct relaxation rates for internal energies

We propose a new ES-BGK model for diatomic gases which allows translational–rotational and translational–vibrational energy exchanges, as given by Landau–Teller Jeans relaxation equations. This is consistent with the general definition of vibrational rotational collision numbers that are also commonly used in DSMC solvers. It proved to satisfy H-theorem give correct transport coefficients, up volume viscosity.