The spray characteristic of the double-line pressure-swirl atomizer with air swirler was investigated using phase Doppler particle analyzer(PDPA).The fuel injection pressure ranged from 0.3MPa to 2.1MPa.The axial air swirler with blade outlet angle of 79°was adopted.The air pressure drop across the swirler ranged from 0.03MPa to 0.15MPa.The change rules of Sauter mean diameter(SMD) and spray cone angle with fuel injection pressure and swirled air velocity were obtained.The results show that in contrast with the situation without swirled air

the spray cone angle increases by 15°~20°and the Sauter mean diameter decreases by 40% which is induced by swirled air under the same fuel injection pressure.