The Combination of Discrete Ordinates and Full-Spectrum k-Distribution Methods to Analysis of Radiative-Conductive Heat Transfer in a Two Dimensional Enclosure

In this research, the combined conductive and radiative heat transfer mechanisms in a two-dimensional enclosure is numerically studied. The bottom wall of this enclosure includes a recess which is simulated with the Blocked-off method. The participating medium in this enclosure is regarded as an air mixture with two radiative gases, CO2 and H2O. This mixture is treated as a homogeneous, scattering, emitting and absorbing medium. To accurately calculate the absorption coefficients distributions across the spectrum as line-by-line, the information of HITRAN2008 database is utilized. In order to simulate the non-gray medium, the full-spectrum k-distribution method is applied; whilst the gray calculations are done using the Planck mean absorption coefficient. The governing equation of this enclosure is the energy equation which is solved via the finite volume method. Besides, the discrete ordinates method is applied to compute the divergence of radiative heat flux in the energy equation. However, the results of this study clearly show that differences between the gray and non-gray mediums for determining the thermal behaviors of the enclosure are strongly dependent on the radiative parameters.