Viscous fingering in volatile thin films

TL;DR

This paper investigates the fingering instability in volatile thin water films caused by evaporation, drawing parallels with the Saffman-Taylor problem and providing solutions for the system's dynamics.

Contribution

It establishes a connection between phase transition-induced fingering in thin films and classical fluid instability problems, offering a new theoretical framework.

Findings

Identified fingering instability in evaporating thin films

Linked the phenomenon to the Saffman-Taylor problem

Developed solutions describing evaporation dynamics

Abstract

A thin water film on a cleaved mica substrate undergoes a first order phase transition between two values of film thickness. By inducing a finite evaporation rate of the water, the interface between the two phases develops a fingering instability similar to that observed in the Saffman-Taylor problem. We draw the connection between the two problems, and construct solutions describing the dynamics of evaporation in this system.