NEW METHOD FOR SOLVING RADIATION TRANSFER PROBLEMS IN EMITTING, ABSORBING, AND SCATTERING MEDIA

The proposed method is based on a novel technique for approximating th e angular dependence of the radiated intensity. The entire range of so lid angles is divided into N cells, which are symmetric relative to th e center oi the sphere. In each of the cells the radiation is assigned in the form of the P-1 approximation, and a system of differential eq uations is obtained to determine the set of local zeroth and first mom ents. In some special cases the proposed approach can be regarded as a generalization of the discrete-ordinates method, which makes it possi ble to solve the problem of selecting the weights in the quadrature fo rmulas in a natural manner. The effectiveness of the method is demonst rated in two one-dimensional test cases. It is shown that in these cas es fairly high accuracy is achieved in the solution of the problem alr eady for N=2. (C) 1997 American Institute of Physics.