Thermochemical nonequilibrium parameter modification of oxygen for a two-temperature model

Thermochemical nonequilibrium parameters of oxygen, O2, for a two-temperature model are proposed in the present work. The rovibrational nonequilibrium and chemical reactions of three low-lying electronic states of O2(X3Σg−, a1Δg, and b1Σg+) are investigated in one-dimensional post-shock flow environments, including the rovibrational state-to-state kinetics and electronic excitations due to heavy-particle collisions. Based on the results of rigorous state-resolved calculations and state-of-the-art shock-tube experimental data, the nonequilibrium parameters of O2 are proposed to improve the two-temperature model accuracy. For shock wave velocities above 3 km/s, the proposed nonequilibrium parameters of the two-temperature model better reproduce the results of the rigorous state-resolved calculations and shock-tube experimental data than do the previous parameters.