Experiments and simulation study on flow field and LBO of trapped vortex combustor with H/L changed

This paper describes lean-blow-out LBO performance of several combustors that utilize trapped vortex in the cavity to provide flame stability. In this study, experiments and simulation study have been employed for variety height to length (H/L) ratios of the cavity. The results of experiments show that when the H/L is 0.8, it gives a minimum pressure drop across the combustor; and very low overall lean-blow-out (LBO) equivalence ratios are obtained over a wide range of primary air flow ratios. Flow field in the cavity is achieved by Large Eddy Simulation (LES). Results of simulation show that when the H/L is 0.8, the core of trapped vortex utilized in the cavity is in the middle of the cavity and the velocity profile of the vortex is well proportioned than other combustors with different H/L ratios. When the H/L is 0.8, the period of vortex whirling is the shortest at the same time. So the simulation results are good for explaining the experiments results.