A Simplified Method for Calculating the Spectral Properties of H2o Under Thermal Nonequilibrium Conditions

A method was developed for calculating the radiative characteristics of water vapor under conditions of vibrational-rotational nonequilibrium. The technique is based on the use of the classical narrowband k-distribution model, which is corrected for nonquilibrium. These corrections include vibrational and rotational partition sums, as well as averaged Boltzmann functions over vibrational and rotational temperatures. To verify the technique, a series of nonequilibrium calculations were carried out, which were compared with the exact line-by-line technique. The comparison was carried out over a wide range of temperatures and pressures and showed good agreement.