Comparison of CK model and line by line method using old and updated parameters/databases

Abstract

Thermal radiation transfer in a 2D enclosure filled with non-gray gases, namely H2O, CO2, or their mixture, is calculated using the line-by-line approach and the correlated-k (CK) model. This study shows the effect of spectral databases on the accuracy of LBL and CK model calculations. Line-by-line calculations were carried out using two databases for high temperature, i.e. the HITEMP1995 and the HITEMP2010 high-resolution databases. Calculations of the CK model were conducted using two sets of parameters, i.e. the old (earlier) parameters {A. Soufiani, J. Taine, High temperature gas radiative property parameters of statistical narrow-band model for H2O, CO2and CO and correlated-k (CK) model for H2O and CO2, Int. J. Heat Mass Transfer 40 (1997) (987–991)} and the new (updated) parameters {(Rivière, P. and A. Soufiani, Updated band model parameters for H2O, CO2, CH4and CO radiation at high temperature, International Journal of Heat and Mass Transfer, 2012. 55(13), 3349–3358)}. The angular and spatial discretization of the radiative transfer equation is performed using the discrete ordinates method and finite volume method, respectively. Seven test cases with different medium temperature (both isothermal and non-isothermal) and homogeneous or non-homogeneous concentrations of participating gases are considered. This study intends to provide a comprehensive evaluation of the CK model with two sets of parameters and LBL method using the HITEMP95 database in a wide range of medium temperatures (from 1000 to 2500 K) and concentration of participating gases (from 10% to 100% mole fraction). The line-by-line results based on the HITEMP2010 high-resolution spectral database are used as benchmarks to evaluate the accuracy of other approximate models. Very good agreement for both the wall heat flux and the radiative source term was observed between the LBL results using the HITEMP2010 database and the results of the CK model in all the test cases. It is concluded that for all considered test cases, the CK method with the new parameters provides better accuracy than with the old ones.