Birth and growth of cavitation bubbles within water under tension confined in a simple synthetic tree

TL;DR

This study investigates the rapid formation and growth of cavitation bubbles in water under tension within microcavities, revealing the dynamics and tension release involved in bubble nucleation and expansion.

Contribution

It provides a detailed analysis of cavitation bubble dynamics in water under tension inside microcavities, including a simple model for the expansion process.

Findings

Stable bubbles form within microseconds after nucleation.

Bubble nucleation releases tens of MPa of tension.

A diffusion-driven model explains the expansion timescales.

Abstract

Water under tension, as can be found in several systems including tree vessels, is metastable. Cavitation can spontaneously occur, nucleating a bubble. We investigate the dynamics of spon- taneous or triggered cavitation inside water filled microcavities of a hydrogel. Results show that a stable bubble is created in only a microsecond timescale, after transient oscillations. Then, a diffusion driven expansion leads to filling of the cavity. Analysis reveals that the nucleation of a bubble releases a tension of several tens of MPa, and a simple model captures the different time scales of the expansion process.