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ENCIT 2020
18th Brazilian Congress of Thermal Sciences and Engineering
EFFECT OF DIFFERENT COMBUSTION MODELS AND CHEMICAL KINETICS INTERMEDIATE STEPS IN THE PREDICTION OF THE RADIATIVE TRANSFER IN TURBULENT METHANE-AIR FLAMES
Submission Author:
Amanda Gonçalves de Figueiredo , RS
Co-Authors:
Amanda Gonçalves de Figueiredo, Larissa Domingues Lemos, Luís Gustavo Pires Rodrigues, Francis França
Presenter: Amanda Gonçalves de Figueiredo
doi://10.26678/ABCM.ENCIT2020.CIT20-0325
Abstract
In this study, it is presented the numerical simulation of a turbulent natural gas flame with focus on the analysis of the radiative heat flux, using the CFD (Computational Fluid Dynamics) Ansys Fluent. The combustion process was solved with the Non-Premixed Combustion - Steady Laminar Diffusion Flamelet (SLDF) model, with detailed reaction mechanism, as well as with the Non-Premixed Combustion - Chemical Equilibrium (CE), with simpler reaction mechanisms, in order to evaluate the sensitivity of the problem with respect to the chemical kinetics. The turbulence was modeled through the k-ε standard model. For the radiation calculation, the weighted-sum-of-graygases (WSGG) was implemented as the spectral model and the discrete ordinates method (DOM) as the spatialdirectional model. This work considered the correlation between the absorption coefficient and the temperature and the temperature self-correlation to account for the effects of turbulence-radiation interaction (TRI). The two models showed physically acceptable results, for instance, showing that the inclusion of TRI effects reduces the flame temperature and increases the radiative heat flux. The results for the SLDF model, with greater detail of the chemical kinetics, showed better results in comparison with experimental data. For the CE model, there was a shift in temperature, species concentration and radiative heat flux in comparison with both the experimental data and the SLDF solution.
Keywords
SLDF, Chemical Equilibrium, WSGG, Turbulence-radiation interaction, CFD
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