Dynamic characteristics of oblique droplet impact on a liquid film

The impact of droplets on liquid films is a fundamental phenomenon in fluid dynamics, with significant implications across various scientific and engineering applications. While much research has focused on normal droplet impacts, where the droplet strikes the liquid surface perpendicularly, the dynamics of oblique droplet impacts remain less understood. This study aims to explore the complex interactions governing oblique droplet impacts on the liquid film. Based on superhydrophobic coating technology, this study proposes a novel experimental method for achieving oblique droplet impacts. Compared to existing methods, this approach offers good experimental repeatability. The experimental setup developed is centered around a droplet generation unit capable of stably producing oblique droplets, with the evolution of the ship's prow-like liquid crown captured using high-speed imaging technology. The effects of the Weber number, impact angle, and liquid film thickness on the evolution and characteristic parameters of the liquid crown were investigated. The model for predicting the variation of the dimensionless liquid crown radius was validated. Additionally, a splashing discrimination method based on the normal K number was introduced, and an empirical correlation for the splashing threshold was established using the soft-margin support vector machine. The findings of this study could pave the way for innovative solutions in industries where precise fluid control is paramount and lay the groundwork for future explorations into more intricate multiphase flow phenomena.