A modification of the narrow band-based WSGG regrouping method for computation time reduction in non-gray gas radiation analysis

• Published in: International journal of heat and mass transfer Vol. 111; pp. 1314 - 1321
• Main Authors: Kang, Sang Hun, Yoo, Chun Sang
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-08-2017; Elsevier BV
• Subjects: Absorptivity; Benchmarks; Carbon dioxide; Gases; Gray gas; Homogeneous mixtures; Non-gray; Radiation; Radiative transfer; Spectral model; Spectrum analysis; Temperature; Total spectrum based model; Weighted sum of gray gases; Spectral model; Total spectrum based model; Non-gray; Weighted sum of gray gases; Radiation
• ISSN: 0017-9310; 1879-2189
• DOI: 10.1016/j.ijheatmasstransfer.2017.04.091

•The narrow band based WSGG regrouping method was modified to be a total band model.•The modified model reduced the required number of times to solve the RTE significantly.•The performance of the modified model was verified by solving four test problems.•With good accuracy, the modified model reduced the computational time remarkably.
In this study, a novel total spectrum-based non-gray model is proposed by modifying the narrow band-based WSGG regrouping (RG-NBW) method. Using the total weighting factor and the total absorption coefficient for each gray gas group, the required number to solve the RTE can be remarkably reduced. To verify the performance of the modified RG-NBW, three-dimensional radiative transfer problems using pure H2O gas with a uniform temperature, a non-homogeneous mixture of H2O and N2 with a uniform temperature, and a mixture of CO2, H2O and N2 with a non-uniform temperature were solved using the discrete ordinate method (DOM) with various non-gray models. The results are compared to benchmark data obtained using the ray-tracing method with the statistical narrow band (SNB) model. For all cases, the results with the modified RG-NBW model show good agreement with the benchmark results as well as results from other models. Furthermore, the modified RG-NBW model requires the shortest computational time after the WSGG model. Therefore, considering the accuracy and computational time, the modified RG-NBW model can be an efficient choice for non-gray gas radiation problems.