Wide Band Correlated-k Approach to Thermal Radiative Transport in Nonhomogeneous Media

Abstract

The correlated-k approach is compared with the exact line-by-line calculations for thermal radiative transport in highly nonhomogeneous media containing water vapor and carbon dioxide. It is shown that the magnitude of the spectral interval over which k-distribution functions are generated can be increased up to approximately 1000 cm−1 for water vapor and 500 cm−1 for carbon dioxide, with only a slight loss of accuracy. Different solution techniques of the radiative transfer equation in nonhomogeneous media are used and compared. The wide band correlated-k method and a simplified approach to the exponential wide band correlated-k method are shown to provide very good results for the cases considered. The calculations include the entire infrared spectrum of water vapor and carbon dioxide for temperatures up to 2500 K.