Techniques for Generating Centimetric Drops in Microgravity and Application to Cavitation Studies

TL;DR

This paper details methods for creating stable centimetric water drops in microgravity and studying cavitation bubbles within them, providing technical insights and stability criteria relevant for microgravity experiments.

Contribution

Introduces an original technique for producing and capturing large stable water drops in microgravity and analyzes cavitation bubble behavior inside these drops.

Findings

Successful generation of quasi-spherical water drops up to 8 ml in microgravity

Formulation of a stability criterion based on drop volume and contact surface

Analysis of bubble size and position effects on drop dynamics after collapse

Abstract

This paper describes the techniques and physical parameters used to produce stable centimetric water drops in microgravity, and to study single cavitation bubbles inside such drops (Parabolic Flight Campaigns, European Space Agency ESA). While the main scientific results have been presented in a previous paper, we shall herein provide the necessary technical background, with potential applications to other experiments. First, we present an original method to produce and capture large stable drops in microgravity. This technique succeeded in generating quasi-spherical water drops with volumes up to 8 ml, despite the residual g-jitter. We find that the equilibrium of the drops is essentially dictated by the ratio between the drop volume and the contact surface used to capture the drop, and formulate a simple stability criterion. In a second part, we present a setup for creating and studying single cavitation bubbles inside those drops. In addition, we analyze the influence of the bubble size and position on the drop behaviour after collapse, i.e. jets and surface perturbations.