A selective spectral discretization model for computing participating-media radiation heat transfer

A selective spectral discretization scheme has been developed for modeling properties of radiatively participating media. This new model automatically assigns more but narrower intervals into wavelength regions where there is strong spectral variation, yielding more accurate representation of the actual properties. New discrete ordinates solutions for a benchmark problem have been obtained in order to assess the impact of the new discretization model. The benchmark problem involves three-dimensional radiative heat transfer in a rectangular enclosure containing CO2, N2, and carbon particles. It was found that depending on the optical thickness of the medium, computation time decreased by 15 to 37% compared to results obtained with an equally spaced discretization model. The values for the surface radiative heat flux and the divergence of the net radiative heat flux both increased.