Measurement and analysis of nitric oxide radiation in an arc-jet flow

On the bases of the centerline enthalpy value deduced from heat transfer measurements and the NOZNT code, it is possible to predict the freestream conditions in an arcjet wind tunnel flow. The translational-rotational and vibrational temperature of NO is nearly reproducible by NOZNT. Relative to the electron and electronic temperatures, the vibrational temperature of N2 and NO are significantly lower at enthalpies of less than 45 MJ/kg. The enthalpy deduced from spectroscopic measurements is in rough agreement with that deduced from heat transfer measurements.