Cold-flow analysis on swirl-stabilized dump combustor by PIV

The characteristics of flow filed under swirling play an important role in the stable work of the central-dump combustor.In this paper,the experimental diagnosis and analysis of the cold-flow field structure of the swirl-stabilized dump combustor are carried out by using PIV. The purpose is to obtain the distribution of the velocity field,the recirculation zone structure and the vorticity of the cold-flow field under different experimental conditions.The experimental results reveal that the cold-flow structure of the swirl-stabilized dump combustor is stable under different inlet air pressures,including a corner recirculation zone,a central recirculation zone and a shear layer.The width of the central recirculation zone increases first and then decreases along the axial direction of central-dump combustor.The length and width of the recirculation zone decrease with the increase of the inlet air pressure.Furthermore,the maximum reverse flow velocity of the recirculation zone is enhanced and the central position of the recirculation zone in swirl-stabilized dump combustor under cold-flow conditions moves closer to the inlet of the cen-tral-dump combustor as the inlet air pressure increases.And the precessing vortex core is formed by swirl in the cold-flow filed of the swirl-stabilized dump combustor.