Paper presented to the 10th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Florida, 14-16 July 2014.
In this work, the transient behavior of the absorbing, emitting, and isotropically scattering medium in radiative equilibrium is examined, using the FTn Finite Volume Method (FTnFVM), in terms of temporal and spatial evolutions of the incident radiation, radiative heat flux, and temperature of the medium. Commonly used convection schemes in computational fluid dynamics (CFD) such as STEP and CLAM are introduced for spatial discetization of the transient radiative transfer equation (TRTE). Also a non-uniform (FTn) angular scheme is used to capture the physics of the radiative wave propagation. The present approach is then validated by comparing with published data and applied to problems of three-dimensional isotropically participating media. It is shown that the FTn FVM reduces largely the ray effects. Also, the false scattering is largely remedied using the CLAM scheme is applied for the angular discretization. In all computations, the CLAM scheme produces more accurate results (with coarse grid) than the step scheme. Using the same (relatively coarse) spatial grid, the CLAM scheme captures the steep gradients and penetration depths more accurately than the step scheme. Then, effects of the scattering albedo and the optical thickness on the incident radiation distributions are presented and discussed.