Abstract
Three-dimensional direct numerical simulation of methane-air turbulent premixed planar flame propagating in homogenous isotropic turbulence is conducted to investigate local flame structure in thin reaction zones. GRI-Mech 3.0 is used to represent methane-air reactions. For a better understanding of the local flame structure in thin reaction zones, distributions of mass fractions of major species, heat release rate and temperature are investigated. The results show that in thin reaction zones, pixel by pixel product of CH_2O-OH or CH_2O-H images have good correlation with heat release rate and is more accurate to discern local flame structures than single OH images. The correlation between heat release rate, principal curvature and tangential strain rate are investigated.
