RADIATIVE-TRANSFER BY THE YIX METHOD IN NONHOMOGENEOUS, SCATTERING, AND NONGRAY MEDIA

A numerical solution of the integral equation of radiative heat transf er using the YIX method involving a mixture or highly anisotropic scat tering particles and a nongray absorbing gas is presented. To validate the three-dimensional calculation, bench mark solutions are establish ed on a model problem using a high-order accuracy method, the product integration method (PIM). Various effects, e.g., the discrete ordinate s sets, first integration point of the YIX quadrature, optical thickne ss of the medium, grid sizes, and spectral resolution on the accuracy of the three-dimensional calculation are discussed. Results for three- dimensional calculations are presented. For all cases, the pressure va riation has less significant effect on the results than those by parti cle density or temperature variations. The three-dimensional nonhomoge neous cases have different trends of variation in radiative flux and d ivergence due to their nonuniform particle density distribution and no nisothermal participating medium. The use of the YIX method with discr ete ordinates for the multidimensional calculations of highly anisotro pic scattering and spectrally-dependent medium is shown to be accurate and flexible.