Abstract: To investigate the relationship between the inject pressure and the spray atomization characteristics, a series tests are taken on a bicentrifugal swirl injector, which works in different injection pressures. The generation and evolution process of the spray are experimentally studied by highspeed photography trials. And the PDA (Phase Doppler Anemometry) tests focus on the stable spray characteristics. On the basis of the experimental results, an equation is developed via nonlinear fitting calculation. The test results show that the injector has good atomization characteristics. Increasing injection pressure makes the spray form more quickly and the spray cone angle becomes larger. The equation can use for predicting the D32 of this bicentrifugal swirl injector in different situations, which could provide data for designer.

Key words: bicentrifugal swirl injector, atomization characteristics, PDA, highspeed photography