To investigate the influence of different swirl numbers on flow structure and aerodynamic characteristics of the model annular combustor with double axial swirler

the isothermal and spray combusting flow fields of the model annular combustor with double axial swirler were measured by a particle image velocimetry (PIV) system.Effects of different swirl numbers on the formation of recirculation zone

profiles of ensemble-averaged velocities (

)

fluctuating velocities (urms

vrms)and Reynolds shear stress u'v' in the combustors were investigated experimentally.Results of the PIV show that influences of different swirl numbers on isothermal and reacting flow fields are considerable.The length of central recirculation zone of reacting flows is shorter than that of non-reacting flows.However

the recirculation velocity

fluctuating velocity and Reynolds shear stress of reacting flows are higher than those of non-reacting flows.The changes of length and recirculation velocity for the central recirculation zone decrease with increase in swirl number under reacting flows.