Many-body dissipative particle dynamics study of droplet impact on superhydrophobic spheres with different size

Abstract

Droplet impact on non-flat surfaces is a common phenomenon, further understandings of this phenomenon can guide a rational design of relevant applications in daily life. The present work numerically studies droplet impact on superhydrophobic solid spheres of different sizes by using many-body dissipative particle dynamics. The simulation results indicate that the time-dependent wrapping angle highly relies on the initial impact velocity and solid sphere size. Four spreading types, bouncing, wrapping, dripping, and bouncing & dripping, can be identified under different impact conditions. It is found that bouncing type prefers to happen at low impact velocity while dripping type is more likely to happen at high impact velocity. Further, on a solid sphere with small size, the dripping type happens at a large range of impact velocity while bouncing type occupies the large range on sphere surface with large size. The contact time is found much shorter for dripping cases than bouncing cases for all sphere sizes.