Dynamics of elastocapillary rise

TL;DR

This paper investigates the complex dynamics of liquid rising between flexible sheets, revealing deviations from classical models through experiments and a theoretical lubrication-based model that captures multiple temporal regimes.

Contribution

It introduces a combined experimental and theoretical framework to understand elastocapillary rise, including a new model that accounts for elasticity effects and multiple temporal regimes.

Findings

Increased elasticity delays equilibrium in capillary rise.

Three distinct temporal regimes are identified and modeled.

Good agreement between experiments and the lubrication-based theory.

Abstract

We present the results of a combined experimental and theoretical investigation of the surface-tension-driven coalescence of flexible structures. Specifically, we consider the dynamics of the rise of a wetting liquid between flexible sheets that are clamped at their upper ends. As the elasticity of the sheets is progressively increased, we observe a systematic deviation from the classical diffusive-like behaviour: the time to reach equilibrium increases dramatically and the departure from classical rise occurs sooner, trends that we elucidate via scaling analyses. Three distinct temporal regimes are identified and subsequently explored by developing a theoretical model based on lubrication theory and the linear theory of plates. The resulting free-boundary problem is solved numerically and good agreement is obtained with experiments.