A VIEW-FACTOR METHOD FOR SOLVING TIME-DEPENDENT RADIATION TRANSPORT PROBLEMS INVOLVING FIXED SURFACES WITH INTERVENING, PARTICIPATING MEDIA

A description is given of a view factor technique for solving time-dependent, non-linear radiative transfer problems. It is believed unique among view factor methods in having the ability to solve problems involving gases or plasmas with emissive and absorptive characteristics which vary in space and time. The radiative characteristics of the enclosing surfaces can also have an arbitrary space and time dependence, and these characteristics can be updated based on an appropriate physical model of the interaction of the background radiation field with the medium. Various sample problems are solved, including a time-dependent solution for concentric spheres filled with a participating medium of arbitrary opacity for a step function source. © 1990.