Study on the spreading and splashing characteristics of droplets impacting a high-speed rotating surface

In the field of aero engines, droplet impact on compressor blades is a common phenomenon that holds significant importance for research. During the mass injection of pre-compressor cooling, a large number of droplets are injected into the intake duct. The droplets that do not evaporate inevitably collide with the compressor blades, affecting their performance and influencing the wet compression process. Therefore, it is essential to study the impact of droplets on rotating surfaces. This paper experimentally investigated the droplet impact process on a rotating surface, considering the effects of impact velocity, rotational speed, and the radius of the impact location. The condition with high rotational speed was investigated especially. Key observations included asymmetric spreading, splashing, and the generation of secondary droplets. The results indicated that varying rotational speeds led to different outcomes following droplet impact. At lower rotational speeds, droplets deposited on the surface and undergo asymmetric spreading. In contrast, at higher rotational speeds, droplets splashed and broke up, producing secondary droplets. Through statistical analysis, the average diameter of the secondary droplets generated by impact on the rotating surface was in the range between 0.08 and 0.25 times the diameter of initial droplet. The correlations for the diameter distribution parameters and the average diameter of the secondary droplets have been proposed.