Vibrational relaxation of CO2(m, n(l), p) in a CO2-N-2 mixture. Part 2: Application to a one-dimensional problem

In order to quantify the relaxation mechanism of CO2(m, n(l), p), the vibra tional level populations are calculated for a particular test-case: the vib rational relaxation of a CO2-N-2 mixture along the stagnation streamline in a reentry problem. The N-2 species is chosen as a collision partner becaus e it is a component existing in numerous gaseous mixtures (cf. Part. 1). Ex citation and deexcitation processes are taken following Nickerson and Herzf eld. The Navier-Stokes code CELHYO for the simulation of hypersonic laminar Viscous flows in chemical and thermal nonequilibrium is used with a new on e-dimensional approach, reduction of the Navier-Stokes equations along the stagnation streamline. Mass fraction and 'vibrational temperature' distribu tions of every vibrational level, considered as an independent chemical spe cies, are presented for the two different CO2-N-2 mixture compositions. The validity of the usual assumptions for the vibrational mechanism is examine d on the basis of the obtained results. (C) Elsevier, Paris.