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ENCIT 2020
18th Brazilian Congress of Thermal Sciences and Engineering
DETAILED NUMERICAL SIMULATION OF THE FLAME-FLOW INTERACTION IN A SLOT-BURNER LAMINAR PREMIXED FLAME
Submission Author:
Rafael Meier , SC
Co-Authors:
Rafael Meier, Amir Antonio Martins Oliveira
Presenter: Rafael Meier
doi://10.26678/ABCM.ENCIT2020.CIT20-0807
Abstract
The purpose of this work is to numerically simulate the premixed flame stabilized in a slot burner with the aim of capturing transport effects that change the local flame stretch and consumption speed. Stoichiometric and lean flames of methane and dimethyl-ether with air at atmospheric pressure are simulated using a two-dimensional cartesian formulation for the low-Mach number compressible flow, with heat transfer and detailed mass transport effects. Reduced mechanisms with 17 species and 58 elementary reactions and 30 species and 175 reactions, with 9 species treated under quasi-steady state, were used for methane and dimethyl-ether respectively. The thermodynamics and kinetics are solved in Cantera while the transport equations are solved using the OpenFoam library. The flame sheet curvature, strain and stretch rates are locally calculated using two different definitions for the location of the flame sheet. The results evidence the effects of the definition of the flame sheet location in the flame kinematics. The behaviors of the Karlovitz number and displacement speed in the positive and negative curvature regions are observed and all flames exhibit approximately the same general correlation between the flame displacement speed normalized by the laminar flame speed (planar flame) and Karlovitz number. The mass fraction of hydrogen along the flame surface presents strong deficiency in the positive curvature region and strong excess in the negative curvature region when compared to the planar, adiabatic flame. The trend is observed not only on the position of the flame surface, but also in the entire distribution along the normal direction as well.
Keywords
Premixed combustion, laminar premixed flame, flame aerodynamics, DNS
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