DISCRETE-VELOCITY COLLISION DYNAMICS FOR POLYATOMIC-MOLECULES

A multispeed discrete-velocity molecular model of a rarefied gas is developed which permits quantitatively accurate simulation of mixtures of molecules of different mass which have both translational and internal rotational energies. In particular, the molecules are represented as having three discrete velocity components and a single discrete internal energy that does not directly affect the translational motion. During binary collisions, rotational and translational kinetic energies are exchanged according to a phenomenological model. Results are presented for the thermal relaxation to equilibrium of mixtures of H-2 and Ne, N2 and O2, and N2 and CO2. Good agreement is found with the corresponding continuous-velocity results.