Analysis of radiative heat transfer in three-dimensional nonhomogeneous, nongray, and anisotropic scattering media

A formulation for analysis of three-dimensional radiative heat transfer in a nonhomogeneous and nongray media with absorbing, emitting and anisotropic scattering is presented. In this method, integral equations relating the gas characteristics (source function, emissive power and heat source) and surface characteristics (leaving intensity, emissive power and heat flux) are developed, using direct exchange factors between differential elements. In the present method, the geometric and property terms of the direct exchange factors are decoupled. This results in significant savings of computation time when the media is nonhomogeneous (radiative properties depend on temperature, pressure or the concentration field) and when bandwise calculations are performed for nongray media. The results obtained via the current method are found to be in excellent agreement with those of the existing solutions for several benchmark problems. New results for a nonhomogeneous spectral case with non-isothermal surfaces are also presented.