Effect of H2O vapor on the vibrational relaxation in hypersonic wind tunnels

This study concerns the development of numerical methods for the simulation of flows in thermochemical nonequilibrium, Its purpose is to take into account some additional minor chemical species in the Navier-Stokes solver CELHYO developed at ONERA, To solve the problem the time-dependent set of equations that governs the flow of the major constituents (N-2, O-2, NO, N, O) and of the contaminants is used, The method is applied to the effect of a contaminant such as H2O vapor on the vibrational relaxation of N-2 and O-2 in two different hyperenthalpic wind tunnels: 1) the ONERA F4 hyperenthalpic wind tunnel and 2) the LBK of the DLR, The modifications of important flow parameters such as the temperatures and the Mach number at the nozzle exits are presented.