Calculation of radiative heat transfer in SF/sub 6/ arc plasmas

Abstract

Radiation transport in SF/sub 6/ are plasmas have been treated for pressures of 0.101, 0.5, and 1.0 MPa. We have investigated the use of an approximate method of partial characteristics. We have calculated spectral absorptivities for SF/sub 6/ plasmas for temperatures from 300 to 35 000 K, and have used these absorptivities to calculate the two functions designated /spl Delta/I and /spl Delta/Sim. These functions are integrals over all radiation frequencies for given line segments with a linear variation of temperature along the line. The /spl Delta/I and /spl Delta/Sim values are functions of the end temperatures and the length of the line, and are used to evaluate radiation transfer from line segments in the plasma where the temperature variation for each line segment is approximated as being linear. The validity of this method of partial characteristics has been demonstrated by comparing exact calculations with the approximate calculations to evaluate radiation intensities, radiation fluxes, and divergence of radiation fluxes for specified temperature profiles. The method of partial characteristics has been applied to one- and three-dimensional calculations of radiative heat transfer in simplified temperature profiles. Agreement up to 10% is obtained with exact calculations, but with a large reduction of computation time.