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COBEM 2021
26th International Congress of Mechanical Engineering
A wide-band formulation for the weighted-sum-of-gray-gases model applied to non-isothermal participating media
Submission Author:
Roberta Juliana Collet da Fonseca , RS
Co-Authors:
Roberta Juliana Collet da Fonseca, Guilherme Crivelli Fraga, Felipe Ramos Coelho, Francis França
Presenter: Roberta Juliana Collet da Fonseca
doi://10.26678/ABCM.COBEM2021.COB2021-0585
Abstract
Thermal radiation contributes greatly to the heat transfer in combustion systems due to the high temperatures. However, the correct prediction of the radiation requires a detailed knowledge of the absorption coefficient of the participating gases, which presents a strongly irregular behavior with the wavenumber. Global spectral models, such as the weighted-sum-of-gray-gas (WSGG) model, present an alternative to the spectral integration of the radiative transfer equation (RTE) with low computational effort and good accuracy when compared to the line-by-line (LBL) integration. In this framework, this paper proposes a methodology for generating correlations for participating species, in which the spectrum is partitioned into a set of regions and the WSGG model is used to solve each spectral interval. The emittances are obtained from LBL calculations for each spectral range, and the pressure-absorption coefficients and temperature coefficients of the WSGG model are obtained for each gray gas. These correlations are tested for non-coupled, radiative transfer calculations and compared to the LBL integration. The results obtained with the proposed method show a reduction of up to a third in deviations from the LBL solution compared to the performance of other formulations of the WSGG model.
Keywords
radiative transfer, participating gases, weighted-sum-of-gray-gases model, line-by-line integration, spectral intervals
