Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
STUDY OF THE INFLUENCE OF SOOT ON THE THERMAL RADIATION ACROSS A UNIDIMENSIONAL FLAME PROFILE USING THE WSGG METHOD
Submission Author:
Cesar Augusto Basso , RS , Brazil
Co-Authors:
Cesar Augusto Basso, Carlos Henrique Lauermann, Bruno de Luca Zimmer Gomes, Francis França
Presenter: Cesar Augusto Basso
doi://10.26678/ABCM.COBEM2021.COB2021-0559
Abstract
Heat transfer by thermal radiation is a complex phenomenon and takes a major role especially at high temperatures, such as in combustion chambers and furnaces. These applications add another level of complexity because of the presence of combustion products that are opaque to radiation and have a spectral dependence. The thermal radiative field is solved by the radiative transfer equation (RTE). In this framework, the method to solve the RTE on a participating medium is the line-by-line (LBL) integration, which provides the exact result, but at a high computational cost. Several methods were developed over the years aiming to provide accurate solutions, with smaller processing required. One of these methods, evaluated on this paper, is the weighted-sum-of-gray-gases (WSGG), which eliminates the spectral dependence of the RTE calculation. This paper evaluates the dependence of the number of gray gases employed on two different WSGG models for a medium consisting of CO2, H2O and soot. The analyzed medium consists of three unidimensional flame profiles, in which the molar fractions of the aforementioned products, as well as the temperature at different points, were evaluated experimentally. Results showed that for a total of four gray gases, the WSGG models provided a satisfactory agreement with the benchmark, where the average error reached a maximum of 4,35% and a minimum 0,16%.
Keywords
thermal radiation, weighted-sum-of-gray-gases model, Numerical simulation, Spectral models, Combustion
