Radiative heat transfer in a packed bed of diffusely reflecting spheres

A new version of the discrete-ordinate method (DOM) is applied to investigate radiative heat transfer in a packed bed of diffusely reflecting spheres. The solution procedure includes expressing the radiation exchange in terms of the radiative intensity leaving surface elements, developing the discrete ordinate approximation for the directional distribution of the intensity entering surface elements, and reversely tracing the entering rays at the surface element considered. The DOM treats all layers of spheres as a system. The results obtained by the DOM agree well with those by the Monte Carlo method using a very large number of bundles. The effects of parameters, such as the surface emissivity, the packing density and the system thickness, are examined.