Nomenclature A = chemical symbol e = total energy per mass unit e A , e D = activation, dissociation energy e Vp = vibrational energy of species p _ e Vp = vibrational energy production of species p due to TV and VV collisions e Vps = vibrational energy gained (lost) by species p due to reaction s f = distribution function J = collisional term in Boltzmann equation K = rate constant k = Boltzmann constant p = pressure Q = quantity Q at equilibrium q = total heat flux q v = vibrational heat flux R = hemispherical body radius T = translation-rotation temperature T V = vibration temperature V = mean velocity (components u and v) V p = mean velocity of component p _ w p = mass production of species p due to chemical reactions _ w Vp = vibrational energy production due to chemical reactions X = longitudinal coordinate in the nozzle x, y = coordinates in the physical plane Y = transverse coordinate in the nozzle = shock standoff distance =R = normalized shock standoff distance = density Subscripts a, b = upstream, downstream from the detached shock b = backward reaction C = chemical f = forward reaction i = internal level p, q = species p, q R = rotation s = reaction s T = translation TV = translation-vibration exchange V = vibration VV = vibration-vibration exchange 0 , 00 = stoichiometric coefficients 1, 2, 3, 4, 5 = associated to species N 2 , O 2 , NO, N, O