The role of drop shape in impact and splash

Qingzhe Liu,Jinyu Zhao,Yuan Liu,Lei Xu,Ye Li,Jack Hau Yung Lo

doi:10.1038/s41467-021-23138-4

Abstract

The impact and splash of liquid drops on solid substrates are ubiquitous in many important fields. However, previous studies have mainly focused on spherical drops while the non-spherical situations, such as raindrops, charged drops, oscillating drops, and drops affected by electromagnetic field, remain largely unexplored. Using ferrofluid, we realize various drop shapes and illustrate the fundamental role of shape in impact and splash. Experiments show that different drop shapes produce large variations in spreading dynamics, splash onset, and splash amount. However, underlying all these variations we discover universal mechanisms across various drop shapes: the impact dynamics is governed by the superellipse model, the splash onset is triggered by the Kelvin-Helmholtz instability, and the amount of splash is determined by the energy dissipation before liquid taking off. Our study generalizes the drop impact research beyond the spherical geometry, and reveals the potential of using drop shape to control impact and splash.

Highlights

The impact and splash of liquid drops on solid substrates are ubiquitous in many important fields
The impact of a liquid drop on a solid substrate is a common phenomenon, which plays a significant role in many important fields, such as agriculture, printing, surface coating, spray cooling, and transmission of respiratory diseases
While extensive studies have been performed on the spherical drops[1,2,3,4,5,6,7,8,9,10,11,12,13,14], much less is understood on the non-spherical counterparts, which frequently appear in many actual situations

Summary

Introduction

The impact and splash of liquid drops on solid substrates are ubiquitous in many important fields. Experiments show that different drop shapes produce large differences in spreading dynamics, splash onset, and splash amount.

Results

Conclusion