The unsteady flow characteristics of low emissions stirred swirls (LESS) combustor swirlers outlet were studied

in combination with experiments and CFD calculation. One-dimensional hotwire tests results show periodic velocity oscillations of 2249Hz existed in the flow field of pilot stage outlet

but didn't appear at main stage outlet. Transient large eddy simulation (LES) calculation had been adopted to verify that velocity at swirlers outlet tested by one-dimensional hotwire has a difference of 8% to real three-dimensional flow. And the simulation results show periodic velocity oscillations of 2331Hz with a difference of 3.6% to experiments. The periodic velocity oscillation phenomenon is dominated by processing vortex core movement in pilot through spectrum analysis and correlation analysis.