Kinetic models for polyatomic molecules with phenomenological energy exchange

Abstract

Models of the collision integral are developed for polyatomic structureless molecules subject to certain classes of phenomenological energy exchange between internal and translational energy modes in binary collisions. The exchange is described either by a model differential cross section for energy scattering or equivalently by a set of pair pseudo-internal coordinates which correlate pre- and post- collision values of the particle energies. Restrictions placed on admissible models of the exchange process are identified and one recently proposed special model is reformulated under these conditions. Chapman–Enskog type transport properties for this model are evaluated and its behavior in the context of the Monte-Carlo direct simulation method is discussed briefly.