Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
NUMERICAL SIMULATION OF A TURBULENT JET DIFFUSION FLAME OF DIMETHYL ETHER USING LES
Submission Author:
Jonatan Ismael Eisermann , RS
Co-Authors:
Jonatan Ismael Eisermann, Alvaro de Bortoli
Presenter: Jonatan Ismael Eisermann
doi://10.26678/ABCM.COBEM2023.COB2023-2065
Abstract
The objective of the present work is to obtain numerical solutions for a turbulent jet diffusion flame of dimethyl ether (DME) in a burner. Thus, a mathematical model based on the combustion process is formulated and solved on a three-dimensional computational mesh of the burner geometry. Under the assumption of low Mach number flow, equations that model a jet diffusion flame include those for the continuity, momentum, mixture fraction, enthalpy/temperature and concentration of the chemical species, which generate a system of partial differential equations highly nonlinear and often difficult to solve. After generating the computational mesh, the fourth-order Finite Difference method is used for Large-Eddy Simulation (LES), with the Smagorinsky model for turbulent viscosity. Using LES, structures larger than the size of the computational mesh are computed explicitly, while small-scale effects are modeled. The resulting algebraic system for the flow is then solved by the Simplified Runge-Kutta method. The chemical part of the flame is modeled by a three-step DME combustion model, with Arrhenius coefficients, and integrated using Rosenbrock’s semi-implicit method. For validation purposes, the numerical results obtained are compared with experimental data from the Sandia National Laboratories and show good agreement. Furthermore, these results help in understanding concepts related to mixing, reaction and combustion of turbulent jet diffusion flames of dimethyl ether that are not yet fully understood.
Keywords
DME jet diffusion flame, Large Eddy Simulation, Finite difference, Simplified Runge-Kutta, Rosenbrock
