Wide band characterization of the total band absorptance of overlapping infrared gas bands

The exponential wide band model is used to establish a simple analytical basis for determining the total band absorptance of two overlapped infrared gas wide bands. Solutions are first developed for homogeneous mixtures. These results are then extended to the nonhomogeneous case by using an existing scaling prescription for the wide band parameters. Comparisons are made with available experimental data for the important case of overlapping carbon dioxide and water vapor bands near 2.7 microns. The agreement is good for the homogeneous cases and is excellent for the nonhomogeneous cases for a wide range of mixture compositions and temperature distributions.