Nonequilibrium Flows Revisited with a Generalized Chapman–Enskog Procedure

Abstract

Chapman–Enskog methods used for the analysis of hypersonic flows in vibrational and chemical nonequilibrium are presented. Taking into account the nonuniqueness of these methods, a more general procedure is developed and is shown to be able to cover all practical situations, including vibration–chemistry interaction. Application to a dissociating diatomic gas flow is proposed and discussed, adopting a step-by-step description, to point out the hypotheses and eventual approximations made at each step. Exact and approximate solutions are tested and compared by computing corresponding flows generated by a strong shock wave.