Effects of Mixture Distribution on the Structure and Propagation of Turbulent Stratified Slot-Jet Flames

Abstract The influence of mixture stratification on the development turbulent flames in a slot-jet configuration has been analysed using Direct Numerical Simulation data. Mixture was imposed at inlet by varying equivalence ratio between 0.6 and 1.0 with different alignments to reaction progress variable gradient: aligned gradients (back-supported), opposed (front-supported) misaligned gradients. An additional premixed case global 0.8 simulated for comparison. flame is shortest front-supported case, followed flame, back-supported gradient being tallest comparable size. This behaviour explained terms variations mean within volume-integrated rate streamwise direction. difference composition these cases results significant burning rate, area, wrinkling brush thickness globally highest while lowest. scalar exhibits qualitatively similar that case. intensity unity major part length but assumes values greater than towards tip where effects curvature become strong. All predominantly exhibit mode combustion flamelet regime, so assumption-based closures, originally proposed combustion, were evaluated priori analysis. which require improved closures have identified existing necessary. It found nature does not performance or parameterisation marginal probability density functions scalars stratified combustion.