Particle image velocimetry (PIV) was used to perform experimental investigation on cold flow field characteristics of low emission trapped-vortex combustor(TVC) model.The varieties of the cold flow field characteristics and the total pressure loss coefficient were obtained.The results show that vortex structures are stable in the model of low emission TVC

and the double vortex structure exists in the trapped vortex area located in the rear of the mainstream

as well as the single vortex structure exists in the trapped vortex area located in the rear of flame transport board.The double vortex system transforms into the single vortex system and the vortex center positions show a little change in these different sections.The center positions of double vortex and single vortex in each section do not change with the inlet Mach number (0.15~0.30) increasing

but the primary vortex area in double vortex system increases

and the secondary vortex area also changes

which is the largest at Mach number of 0.2.The velocities of airflow in the primary combustion zone and the edge of the vortex

the vortexes strength

and the total pressure loss coefficient increase with the inlet Mach number changing from 0.15 to 0.3.