Line by line benchmark solutions for radiative heat transfer in 2D irregular enclosures with non-gray media

Thermal radiation heat transfer in two-dimensional complex (irregular) enclosures containing non-gray gases, namely CO2/H2O/N2 mixtures, is calculated. The meshless Natural Element Method (NEM) is used for spatial discretization and the Discrete Ordinates Method (DOM) is employed for angular discretization of the radiative transfer equation. The Line-by-Line (LBL) and the correlated-k model (CK) models are used to model the spectral radiative properties of the participating gases. To obtain the most accurate results, the updated HITEMP spectroscopic database i.e. HITEMP2010 is employed in LBL calculations and the updated parameters (based on the HITEMP2010) is used in the CK calculation. The objectives of this study are threefold: (1) to combine a meshless natural elements method with LBL and the CK spectral models for the solution of radiative transfer problems in irregular (complex) enclosures, (2) to evaluate the accuracy of the CK model by comparing its results against the LBL results, and (3) to provide benchmark solutions for radiative heat transfer in irregular enclosures with the HITEMP2010 as the most accurate spectral database at high temperatures. Calculations are carried out for isothermal/non-isothermal and homogeneous/inhomogeneous mixtures of CO2/H2O/N2 gases. The present LBL results can serve as benchmark results for validating other approximate models in gas radiation heat transfer calculations in 2D complex enclosures. Results show that the CK results are in good agreement with those of the LBL model.