Extended Progress Variable and Mixture Fraction Model for Turbulent Premixed Combustion

A approach combining a progress variable and a mixture fraction transport equation is used to describe a turbulent premixed flame with non-uniform equivalence ratio, caused by lateral entrainment of air. The equations are solved using a projection-based fractional step method for low-March number flow in a large eddy simulation (LES) framework. The numerical method with a simply extended model is applied to simulate a slot Bunsen flame in two dimensions. The computed mean flame front is comparable to that of experiment and 3D computation using detailed chemical kinetics. The present numerical simulation can also well predict the flame height and the global turbulent flame speed. The computed flame surface density profiles match with those of the experiment.