Thermochemical Nonequilibrium Modeling of O₂

Abstract

The vibrational nonequilibrium in the electronically excited states of ${\mathrm{O}}_2\left({X}^3{\Sigma}_g^{-}, {a}^1{\Delta}_g,{b}^1{\Sigma}_g^{+}\right)$ is investigated in the one-dimensional post-shock flows. The electronic and rovibrational state-to-state kinetics due to the heavy-particle collisions are employed to describe the electronic and rovibrational energy transitions. In the 1D post-shock flow calculations, it is observed that the vibrational relaxations of ${\mathrm{O}}_2\left({X}^3{\Sigma}_g^{-}\right)$ are more significant than those of the ${\mathrm{O}}_2\left({a}^1{\Delta}_g,{b}^1{\Sigma}_g^{+}\right)$ because the electronic excitation due to the heavy-particle collisions is not efficient.