The non-equilibrium and frozen flows of scramjet nozzle were numerically simulated to study the effects of radical recombination on the nozzle performance,based on 13-species and 33-step H2/Air finite-rate chemistry reaction mechanism.The numerical results show that the recombination occurs during the expansion in scramjet nozzle and that is beneficial to the nozzle performance.With the increase in the flight Mach,the effects of radical recombination on the nozzle performance are more significant.The nozzle...