Stability and reconstruction of inverse gravity films (Review Article)

Abstract

The paper traces retrospectively the development of the concept of stability of liquid films formed on downward facing surfaces (inversed gravity films). The original scenario of the instability development proposed by Rayleigh does not contain the concept of a critical state, after reaching which the flat stable inversed gravity film transforms into a corrugated modification whereas the film thickness is slightly increased. Both the general understanding of the events which occurred at the critical point, and the possibility of discussing the full-scale instability including its definition and various scenarios of inversed gravity films reconstructions, have been developed only recently. The aim of this study is to outline a consistent picture of droplet instability at its different stages starting from the threshold point and up to the formation of a stationary corrugation (surface shape reconstruction). The computational part of the paper is complemented with a series of specially performed experiments, which confirm the main predictions of the theory.