DNS Study of Spherically Expanding Premixed Turbulent Ammonia-Hydrogen Flame Kernels, Effect of Equivalence Ratio and Hydrogen Content

In this study, 3D premixed turbulent ammonia-hydrogen flames in air were studied using DNS. Mixtures with 75%, 50% and 25% ammonia (by mole fraction the fuel mixture) equivalence ratios of 0.8, 1.0 1.2 studied. The studies conducted a decaying turbulence field an initial Karlovitz number 10. flame structure influence ratio first It was observed that increase smoothened out small scale wrinkles while leading to strongly curved edges. Increasing amount hydrogen mixtures also led increasingly distorted flames. These effects are attributed local increases due preferential diffusion hydrogen. curvature on chemistry by looking at consumption rates key reactions. highly mobile H2 H species responsible for differential positively negatively regions flame. indication critical mixture observed, after which trends reactions involving radical flipped respect sign curvature. This has implications NO formation. Finally, spatial profiles heat release temperature studied, showed brush lean case width propagation is slow stoichiometric rich cases suppression effects.