Thermochemical Nonequilibrium Modeling of Electronically Excited Molecular Oxygen

Abstract

The thermochemical nonequilibrium of the three lowest lying electronic states of molecular oxygen, O2(X Σg , a ∆g, b Σg ), through interactions with argon is studied in the present work. The multi-body potential energy surfaces of O2+Ar are evaluated from the semiclassical RKR potential of O2 in each electronic state. The rovibrational states and energies of each electronic state are calculated by the quantum mechanical method based on the present inter-nuclear potential of O2. Then, the complete sets of the rovibrational stateto-state transition rates of O2+Ar are calculated by the quasi-classical trajectory method including the quasi-bound states. The system of master equations constructed by the present state-to-state transition rates are solved to analyze the thermochemical nonequilibrium of O2+Ar in various heat bath conditions. From these studies, it is concluded that the vibrational relaxation and coupled chemical reactions of each electronic state needs to be treated as a separate nonequilibrium process, and rotational nonequilibrium needs to be considered at translational temperatures above 10,000 K.