154 Short-Pulse Collimated Radiation in a Participating Medium Bounded by Diffusely Reflecting Boundaries

A two-dimensional model is presented in this article to study the transient radiative transfer phenomena involved in a participating medium subjected to short pulse collimation. The model assumes the medium bounded by diffusely emitting and reflecting boundaries, one of the boundaries is irradiated with a short pulse collimated beam. The finite volume method is applied to solve the transient radiative transfer equation governing the physical phenomena. The fully implicit scheme is used to discretize the transient term. In the proposed approach, intensity can directly be evaluated by solving the governing transient radiative transfer equation. The effects of scattering albedo and emissivity on the transmitted and reflected flux are studied. The performance of two different spatial schemes: STEP and CLAM are also been tested. It is seen that the CLAM scheme gives results to a greater accuracy and hence, correctly predict the speed of photon whereas STEP scheme over predicts the same.