Localized Rayleigh Instability in Evaporation Fronts

TL;DR

This paper reveals a localized Rayleigh instability in thin liquid films during evaporation, where the instability causes an isolated narrowing rather than widespread breakup, influenced by nonuniform curvature.

Contribution

It introduces the concept of localized Rayleigh instability caused by nonuniform curvature, differing from traditional extended instabilities in liquid films.

Findings

Localized instability leads to filament narrowing

Curvature nonuniformity triggers the instability

Implications for evaporation dynamics of thin films

Abstract

A qualitatively different manifestation of the Rayleigh instability is demonstrated, where, instead of the usual extended undulations and breakup of the liquid into many droplets, the instability is localized, leading to an isolated narrowing of the liquid filament. The localized instability, caused by a nonuniform curvature of the liquid domain, plays a key role in the evaporation of thin liquid films off solid surfaces.