Computation and experiment of nonequilibrium nozzle flow of arc-heated air

Numerical simulations of a nonequilibrium nozzle flow of arc-heated air were carried out using an eight-temperature model composed of translational, N-2-rotational, O-2-rotational, NO-rotational, N-2-vibrational, O(2-)vibrational, NO-vibrational, and electron temperatures. The on-axis profile of each temperature in the nozzle is shown and the thermal characteristics of the nozzle flow are discussed. Measurements of NO emission spectra were also made at wavelengths 220-265 nm at the nozzle exit to determine NO rotational temperature by a curve-fitting method. Computed rotational temperature of NO at the nozzle exit was compared with the experimental temperature to discuss the nozzle flow model introduced to the present numerical analysis. Moreover, the present computation was applied to a nozzle flow in another arcjet facility. The comparison between the computed NO rotational temperature and the experimental temperature showed reasonable agreement.