Numerical investigation of flame flashback in LDI combustor

CAO Min, ZHANG Wenpu

(School of Aeronautics and Astronauties, Zhejiang University, Hangzhou 310027, China)

 Abstract: Aiming at the problem of flashback in combustion stability,a large eddy simulation was used to investigate the flashback characteristic of lean direct injection combustor.The flashback here was refered to a phenomenon that the flame propagates from the combustor into the premixed zone, which contains complex interaction among the sound waves,turbulence and reactions.It is one of the key issues in the combustion research.The mixture fraction/PDF equilibrium chemistry model and discrete phase model with software Fluent were adopted to simulate the cold flow and hot flow,and the flashback was observed. WALE model was used as the subgrid model. The results indicate that large eddy simulation can predict the flow field well, there exists a centeral recirculation zone in the LDI combustor, numerical results are in good agreement with experimental data, flame flashback in LDI combustor occurs around the centerline and during flashback, the central recirculation zone moves upstream,which pulls the flame upstream propagation,and finally leads to flashback.