Spinning Twisted Ribbons: When Two Holes Meet on a Curved Liquid Film

TL;DR

This paper investigates the complex dynamics when two holes meet on a curved liquid film, revealing the formation of a spinning twisted ribbon that influences droplet formation, with implications for various scientific and industrial processes.

Contribution

It introduces the novel observation of spinning twisted ribbons forming during multiple-hole rupture on curved films and models their evolution, contrasting with flat film behavior.

Findings

Spinning twisted ribbons form when two holes meet on curved films.

The geometry and dynamics of the ribbons are characterized and modeled.

This phenomenon differs significantly from rupture on flat films.

Abstract

The rupture of a liquid film, where a thin liquid layer between two other fluids breaks and forms holes, commonly occurs in both natural phenomena and industrial applications. The post-rupture dynamics, from initial hole formation to the complete collapse of the film, are crucial because they govern droplet formation, which plays a significant role in many applications such as disease transmission, aerosol formation, spray drying nanodrugs, oil spill remediation, inkjet printing, and spray coating. While single-hole rupture has been extensively studied, the dynamics of multiple-hole ruptures, especially the interactions between neighboring holes, are less well understood. Here, this study reveals that when two holes 'meet' on a curved film, the film evolves into a spinning twisted ribbon before breaking into droplets, distinctly different from what occurs on flat films. We explain the formation and evolution of the spinning twisted ribbon, including its geometry, corrugations, ligaments, and orbits, and compare the experimental observations with models. We compare and contrast this phenomena with its counterpart on planar films. While our experiments are based on the multiple-hole ruptures in corona splash, the underlying principles are likely applicable to other systems. This study sheds light on understanding and controlling droplet formation in multiple-hole rupture, improving public health, climate science, and various industrial applications.