Calculation of arcjet constrictor plasma temperatures using a Monte Carlo method for radiation transfer

A one-dimensional, axisymmetric, Monte Carlo radiative transfer method has been developed to calculate the energy transfer and temperature profiles of moderate to high pressure cylindrical electric arc columns. The model includes the energy transfer due to the emission and absorption of a non-gray gas and thermal conduction but neglects convection. The thermal and electrical conductivities and the wavelength dependent spectral absorptivities are calculated based on an assumption of local thermodynamic equilibrium (LTE). To verify the method, calculations were performed for the case of an electric arc in air at 30 atm pressure. The results were compared to those obtained from an earlier calculation which used the diffusion approximation for the radiative transfer. This case is representative of conditions that are typical of constrictors in arc heaters. The method was then applied to an arc in NH3 at 1 atm for conditions that are typical of the constrictor in arcjet thrusters.