The flow field and spray characteristics of a high shear air-blast nozzle were investigated numerically and experimentally. Particle dynamics analyzer (PDA) was employed to experimentally study on the velocity field and spray field of the high shear air-blast nozzle under different air-liquid ratios. And through numerical calculation of the flow field of the nozzle

the calculated results agreed with the experimental data. The results show that the design of high shear air-blast nozzle is reasonable. Two swirl air flows could finish strong momentum exchange inside the nozzle

and fuel is highly sheared. The high shear air-blast nozzle can achieve good atomization under wide regulation ratios. When the air-liquid ratio is of 10 times

the Sauter mean diameter distribution of spray is between 20-60μm. With the increase of air-liquid ratio

line averaging Sauter mean diameter decreases. The calculation model of Sauter mean diameter is derived for the nozzle. The results can provide references for high shear air-blast nozzle design.