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ENCIT 2022
19th Brazilian Congress of Thermal Sciences and Engineering
Development and application of a wide-band approach based on the weighted-sum-of-gray-gases model for problems with non-gray walls
Submission Author:
Roberta Juliana Collet da Fonseca , RS
Co-Authors:
Roberta Juliana Collet da Fonseca, Francis França, Guilherme Crivelli Fraga
Presenter: Roberta Juliana Collet da Fonseca
doi://10.26678/ABCM.ENCIT2022.CIT22-0354
Abstract
The spectral modeling of the radiative properties of participating gases is one of the most significant research fields in the heat transfer by thermal radiation. However, the correct representation of the spectral dependence of the absorption coefficient of a participating gas, such as water vapor and carbon dioxide, is a difficult undertaking, since it depends on the solution of the line-by-line (LBL) integration to accurately solve the radiative transfer equation (RTE). When the medium is contained within a non-gray enclosure and the spectral dependence of the boundaries must also be taken into account, this complexity increases even further. In this framework, to compute the radiative exchanges between a participating medium and non-gray walls, the present paper proposes the development and application of a wide-band model based on the weighted-sum-of-gray-gases (WSGG). In this method, the spectrum is divided into a set of regions and these spectral intervals are synchronized with the spectral emissivity distribution of the non-gray boundaries. The WSGG model is used to solve the contribution of the radiative heat flux and radiative heat source of each one of these segments. The results show that the proposed methodology led to maximum deviations of 8% compared to the LBL solution.
Keywords
thermal radiation, non-gray walls, spectral intervals, wide-band models
