STATE-TO-STATE APPROACH IN THE KINETICS OF AIR COMPONENTS UNDER REENTRY CONDITIONS

A state-to-state vibrational kinetics for air components including rec ombination-dissociation processes as well as the formation of NO throu gh the reaction between vibrationally excited nitrogen molecules and a tomic oxygen has been inserted in a monodimensional fluid dynamic code , describing the boundary layer surrounding a body under re-entry cond itions. The results show that the formation of NO is strongly enhanced by the nonequilibrium vibrational distribution of N-2 formed during t he recombination process. This kind of distribution is responsible for the non-Arrhenius behavior of dissociation constants of N-2 and O-2 a s well as the NO formation rate as a function of instantaneous tempera ture.