Numerical study on effects of large curved superhydrophobic surfaces on droplet post-impact dynamics

Abstract

Droplet impact on curved solid surfaces is a widely observed phenomenon. Curved surfaces with large object-to-droplet ratios, termed size factor, are expected to impose influence on the droplet post-impact dynamics. In this work, droplet impact on curved surfaces with a range of size factors is simulated. The simulation results show that both the size factor and initial impact velocity can significantly affect the post-impact dynamics of the droplet. Three post-impact dynamics states, stick state, bounce state, and shatter state are identified and found to highly depend on the size factor and impact velocity. Besides, the spreading dynamics, contact time for bouncing droplets, and the detachment velocity also depend on the size factor and initial impact velocity to some degree. Splashing of droplet at higher impact velocity is also discussed. The current study could inspire the design of functional surfaces with water-resistant and anti-icing properties in relevant applications.