State-to-state approach in the kinetics of air components under re-entry conditions

A state-to-state vibrational kinetics for air components including recombination-dissociation processes as well as the formation of NO through the reaction between vibrationally excited nitrogen molecules and atomic oxygen has been inserted in a monodimensional fluid dynamic code, describing the boundary layer surrounding a body under re-entry conditions. The results show that the formation of NO is strongly enhanced by the nonequilibrium vibrational distribution of N2 formed during the recombination process. This kind of distribution is responsible for the non-Arrhenius behavior of dissociation constants of N2 and O2 as well as the NO formation rate as a function of instantaneous temperature.