Abstract
Direct numerical simulations (DNS) of propane-air turbulent premixed flames propagating in two-dimensional homogeneous isotropic turbulence are conducted to clarify the structure of turbulent premixed flames. Detailed kinetic mechanism including 325 elementary reactions and 53 reactive species are used to simulate propane-air flames in turbulence. Local heat release rates are well correlated with curvatures of the flame front. Flames convex toward the burnt gas show large heat release rate, while those concave toward the burnt gas show relatively low heat release rate. C_3H_8 consumption rate is also well correlated with curvatures of the flame front. Flame elements with large curvature show large C_3H_8 consumption rate. Flame elements compressed by turbulence possess large NO production rate, while stretched flames possess relatively small production rate.
