A numerical simulation using the VOF (volume of fluid) interface tracking method and RNG(renormalization group)turbulence model was carried out in order to deeply understand the atomization mechanism of the open-end swirl injector. The feasibility of the numerical calculation was verified by using PDPA(phase Doppler particle analyzer) and camera to measure the injector exit velocity and the spray angle. The central air core and the recirculation regions in the injector were captured. And the interaction between the tangential inlets and swirling chamber was revealed. What's more

the evolving characteristic of the liquid film thickness and the development law of the internal and external velocity field were emphatically analyzed. With the increasing of the pressure drop

the breaking length decreases while the opening length and the spray angel increase. The unique mechanism of the open-end swirl injector is revealed so it can be helpful to predict of the atomization performance and the structure optimization.