The heavy windlass: Buckling and coiling of an elastic rod inside a liquid drop in the presence of gravity

TL;DR

This paper investigates how gravity influences the buckling and coiling behavior of an elastic rod inside a liquid drop, extending understanding of the windlass effect beyond small systems dominated by surface tension.

Contribution

It introduces a model that accounts for gravity's role in the buckling and coiling of elastic rods within large liquid drops, revealing new dynamics in the windlass mechanism.

Findings

Gravity alters the buckling threshold of the elastic rod.

Large drops with significant weight modify the coiling behavior.

Surface tension effects are complemented by gravitational forces in large systems.

Abstract

A liquid drop sitting on an elastic rod may act as a winch, or windlass, and pull the rod inside itself and coil it. This windlass effect has been shown to be generated by surface tension forces and to work best for small systems. Here we study the case where the drop is large enough so that its weight interferes with surface tension and modifies the windlass mechanics.