Numerical Simulation of Methane Triple Flames: Effect of Equivalence Ratio on the Flame’s Structure

The present study offers a numerical investigation of the structure of triple flames formed in flow fields with a given equivalence ratio (Φ = 1.8) in a two-dimensional duct flow configuration. We first use a mixture of methane and air at uniform temperature (T = 300 K) and velocity (0.3 m/s) at the inlet of the duct. The validation of numerical result is done by comparing with the experimental measurements of I.K. Puri, S.K. Aggarwal, S. Ratti and R. Azzoni. Second, detailed structure and chemical reactivity information are presented for four different equivalence ratios in order to determine its impact on flame structure. Triple flames consist of three reaction zones which merge at triple point and may be produced in stratified mixtures undergoing combustion. They may play some important roles in the stabilization and liftoff of laminar non premixed flames, in the building of new combustion models and in the mechanism of NOx reduction.