Development of multi-group full-spectrum k-distribution look-up table for nonhomogeneous gas media radiative transfer

Abstract

A multi-group full-spectrum k-distribution (MG-FSK) look-up table has been constructed for gas mixtures within a large range of thermodynamic states for two species, i.e., CO2 and H2O. The multi-group k-distribution of a mixture is assembled directly from the summation of the linear absorption coefficients of two species. A systematic approach is introduced in this paper to generate the MG-FSK look-up table. Gauss-Chebyshev quadrature is chosen to reduce the size of the look-up table. To efficiently obtain accurate a-values and k-values for arbitrary thermodynamic states from tabulated values of gas mixture, a 5-D linear interpolation method is employed. A large number of thermodynamic states have been carried out to test accuracy of the MG-FSK look-up table. Results show that, using the MG-FSK look-up table can provide excellent accuracy compared with the exact results. The relative error of the radiative heat flux using MG-FSK look-up table is generally no more than 1%, and the maximum relative error in all calculation examples is 6.59%. For non-isothermal gas radiation, MG-FSK look-up table shows higher accuracy than FSCK look-up table.