Short time dynamics of water coalescence on a flat water pool

TL;DR

This study investigates the rapid dynamics of water droplet coalescence on flat water surfaces using ultrafast X-ray microscopy, revealing how extreme curvature differences can significantly alter hydrodynamic behavior.

Contribution

It provides the first experimental evidence that extreme curvature differences can modify water coalescence dynamics, challenging existing theories.

Findings

Extreme curvature differences influence coalescence behavior

Ultrafast X-ray microscopy captures short-time coalescence dynamics

Proposed explanation for curvature-induced modifications

Abstract

Coalescence is an important hydrodynamic event that frequently takes place in nature as well as in industry. Here we provide an experimental study on short time dynamics of water coalescence, particularly when a water droplet comes in contact with a flat water surface, by utilizing high-resolution high-penetration ultrafast X-ray microscopy. Our results demonstrate a possibility that an extreme curvature difference between a drop and a flat surface can significantly modify the hydrodynamics of water coalescence, which is unexpected in the existing theory. We suggest a plausible explanation for why coalescence can be modified by an extreme curvature difference.