Effect of Thermodiffusion on Non-premixed Flame in MILD Regime Using a Modified Reacting Solver.

Abstract

Numerical simulations for moderate and intense low oxygen dilution (MILD) combustion with essential solvers and detailed mechanisms involve more complications and computational time. Various advanced combustion modeling techniques have recently been developed to study MILD combustion characteristics. However, every combustion model has specific issues predicting the temperature and emissions of the MILD combustion flames. The diffusive nature of the MILD flame is considered, and individual Lewis numbers are investigated on a nonpremixed flame. The current study analyzes the methane/hydrogen flame propagation with different Lewis number combinations in a hot co-flow environment. Individual Lewis numbers for methane and hydrogen are investigated from stochiometric to ultra-rich mixtures in non-premixed flames. Several numerical simulations are performed in the OpenFOAM9 environment using a modified EDC model with tuned turbulence and combustion model constants. The numerical simulation results with hydrogen and methane Lewis numbers of 0.4 and 0.9, respectively, show promising agreement with the experimental findings of Dally1, et al. Various combustion parameters are studied with different CH4 and H2 Lewis number combinations. In addition, the unity Lewis number case is simulated and compared to the situations that are taken into consideration.
Subjects
FLAME; HYDROGEN flames; THERMOPHORESIS; COMBUSTION; COMPUTER simulation

Description