Rotational motion of a droplet induced by interfacial tension

TL;DR

This paper investigates how interfacial tension and Marangoni flow can cause a droplet to spontaneously rotate, supported by theoretical calculations and experimental validation.

Contribution

It provides a theoretical model explaining spontaneous droplet rotation induced by interfacial tension and validates it with experiments.

Findings

Droplet spontaneously rotates under certain size conditions.

Advective nonlinearity breaks symmetry leading to rotation.

Theoretical predictions match experimental observations.

Abstract

Spontaneous rotation of a droplet induced by the Marangoni flow is analyzed in a two-dimensional system. The droplet with the small particle which supplies a surfactant at the interface is considered. We calculated flow field around the droplet using Stokes equation and found that advective nonlinearity breaks symmetry for rotation. Theoretical calculation indicates that the droplet spontaneously rotates when the radius of the droplet is an appropriate size. The theoretical results were validated through comparison with the experiments.