KINETICS OF THE N-2-]NO+N REACTION UNDER THERMODYNAMIC NONEQUILIBRIUM(O)

The first Zeldovich reaction, N-2 + O --> NO + N, plays a major role i n nitric oxide formation in reentry flows, combustion, and discharge f low systems, The kinetics of this reaction is uncertain under the stro ng thermodynamic nonequilibrium conditions and extremely high temperat ures that often characterize these flows, We assess the influence of t hese conditions on the reaction rate using detailed quasiclassical tra jectory calculations on the (3)A '' surface obtained from ab initio co ntracted configuration interaction data, The effect of reactant energy modes on the rate constant is analyzed and a functional dependence of the rate constant on the vibrational, rotational, and translational t emperatures is obtained, It is seen that strong nonequilibrium can red uce the rate constant by a factor of 5-6, In addition, the energy of t he NO molecules formed by this reaction is determined and its dependen ce on the reagent energy is studied, The vibrational and rotational di stributions of the product NO molecules under typical re-entry flow co nditions are obtained and are found to be nearly Boltzmann, For strong nonequilibrium cases, NO is formed at high vibrational and rotational temperatures, in accordance with the bow-shock ultraviolet flight exp eriments.