The k-moment method for modeling the blackbody weighted transmission function for narrow and wide band radiative properties of gases

This paper presents the k-moment method, based on the calculation of the moments of the absorption coefficient, to calculate the blackbody-weighted transmission function for modeling narrow and wide band radiative properties of gases. The spectral averaging is performed on band widths of the order from 25 to 600cm-1. The spectrally averaged integral formulation of the radiative transfer equation is established and associated blackbody-weighted transmission function approximate expressions are derived from a series reversion technique. The second and third order k-moment formulations are assessed through comparisons with line-by-line reference results in the case of pure carbon dioxide at atmospheric pressure and for temperatures ranging from 300 up to 2300 K.