Vibrational relaxation of CO 2( m, nl, p) in a CO 2N 2 mixture. Part 2: Application to a one-dimensional problem

Abstract

In order to quantify the relaxation mechanism of CO 2( m, n l , p), the vibrational level populations are calculated for a particular test-case: the vibrational relaxation of a CO 2N 2 mixture along the stagnation streamline in a reentry problem. The N 2 species is chosen as a collision partner because it is a component existing in numerous gaseous mixtures (cf. Part. 1). Excitation and deexcitation processes are taken following Nickerson and Herzfeld. The Navier-Stokes code CELHYO for the simulation of hypersonic laminar viscous flows in chemical and thermal nonequilibrium is used with a new one-dimensional approach, reduction of the Navier-Stokes equations along the stagnation streamline. Mass fraction and ‘vibrational temperature’ distributions of every vibrational level, considered as an independent chemical species, are presented for the two different CO 2N 2 mixture compositions. The validity of the usual assumptions for the vibrational mechanism is examined on the basis of the obtained results.