Radiative transfer in spectrally-dissimilar absorbing-emitting-scattering adjacent mediums

The structure of a radiation field in a cylindrical medium having two regions of different, but uniform absorption and scattering coefficients is analyzed. Fundamental aspects of the problem are elucidated by considering the case of a gray medium. It is shown for example that, for unequal absorption coefficients in the two regions, both emission and absorption rates are discontinuous at the interface of the two regions, but the heat flux and incident radiation are continuous. As an application of the analysis, the influence on heat transfer of the spatial distribution of particles in a coal-burning swirl combustor is investigated. In the example application, spectral calculations are performed spanning the broad frequency range of the thermal radiation spectrum.