FGM History of engineering & technology LES Lewis number autoignition modelling bending effect boundary layer flashback confined countergradient transport direct numerical simulations engine knock evaporative cooling flame curvature flame surface density flame surface wrinkling modeling flame-wall interaction flamelet generated manifold gasoline surrogates hydrogen iso-scalar non-material surfaces large eddy simulation modeling molecular transport premixed methane premixed turbulent combustion reaction surface area reaction waves reduced chemical kinetics scalar dissipation rate sidewall quenching