In order to explore a way to improve the spray performance under low injection pressure differential

from the perspective of regulating airflow split

effects of airflow ratio of primary swirler to secondary swirler on the spray characteristics of dual-axial swirl cup were studied by experimental system. The influences of airflow ratio on mean drop diameter

drop size distribution parameter and spray angle were obtained. The experimental results indicated that increasing the airflow ratio

the mean drop diameter decreased

and the swirl cup had good spray property over a wide range of injection pressure differential

which could achieve the improvement of the spray performance under low injection pressure differential. The spray angle increased with the airflow ratio

and firstly increased but then remained constant with the injection pressure differential. For a given total airflow of swirl cup

the optimal comprehensive spray performance was obtained when the airflow ratio was about 1.