Dissociation and vibrational relaxation in a spatially homogeneous mixture CO2/CO/O

Abstract

Vibrational relaxation and dissociation of CO2 molecules is studied in a spatially homogeneous mixture CO2/CO/O. Equations for macroscopic parameters based on three-temperature, two-temperature and one-temperature vibrational distributions are solved numerically for different initial conditions. The influence of kinetic models on the gas temperature variation, mixture composition and dissociation rate is studied. The comparison of the results obtained with the use of two analytical approximations for the vibrational relaxation time is discussed. The impact of initial excitation of the combined symmetricbending and asymmetric modes on the gas temperature and dissociation rate is also studied in the paper. CO2 dissociation is found to proceed much faster in the case of strongly initially excited the combined mode compared to the case of initial excitation of the asymmetric mode. The results obtained may be helpful for the choice of an appropriate kinetic model for numerical flow simulations of mixtures containing CO2 molecules. Refs 16. Figs 6.