Effect of swirler types on spray characteristics of airblast atomizer

The influences of different swirler types on the spray characteristics of dual-stage swirl airblast atomizer were investigated by using a combination method with experiment and numerical calculation.Particle image velocimetry （PIV） was applied to measure the downstream flow field structures of different swirler types，a high-speed camera and a laser particle size analyzer were used to photograph the atomization morphology，measure Sauter mean diameter （SMD） and Rosin-Rammler distribution under different air flow and fuel flow rates.At the same time，the secondary atomization characteristics of the dual-axial swirl cup were obtained by using the numerical calculation method.The results showed that，under the same working conditions，the atomization cone angle of the atomizer with two-stage axial swirler was slightly larger than that of the radial swirler.The atomization process with dual-stage radial swirler mainly relied on its centrifugal atomization of the atomizer，and the air assisted atomization was limited.The atomization process with dual-stage axial swirler was mainly affected by the first atomization of the atomizer when the pressure loss of swirl cup was small.With the increase of pressure loss，the air assisted atomization effect gradually played a major role.The numerical calculation results were in good agreement with the experimental results，indicating that the numerical calculation method can be used to simulate the atomization process of the dual-stage swirl airblast atomizer，and the numerical results can be used to explain the secondary atomization process.