Effects of Differential Diffusion on Flame Structure of Non-premixed Ammonia/Methane Combustion

Large eddy simulation (LES) employing a flamelet/progress variable (FPV) model based on detailed chemical kinetics were conducted to investigate effects of differential diffusion in non-premixed ammonia/methane/air combustion. From the comparisons between the cases using differential diffusion (non-unity Lewis number assumption) and unity Lewis number assumption, the numerical results show that the flame height shortens in the absence of differential diffusion. The flame structure is also influenced by differential diffusion in a significant manner. Further, experiments have also been performed to verify the accuracy of the simulation.