Dynamics of Hanging Droplets from Liquid Interfaces

TL;DR

This study uses 3D simulations and theoretical modeling to show that heavier droplets can hang from lighter liquid surfaces due to surface tension, with implications for various scientific and engineering fields.

Contribution

The paper introduces the first numerical demonstration and theoretical analysis of heavier droplets hanging from lighter liquid surfaces via surface tension.

Findings

Heavier droplets can remain suspended from lighter liquids due to surface tension.

Simulation results align closely with analytical force balance models.

The study explores the impact of droplet size and release height on hanging behavior.

Abstract

The impact of a heavier droplet into a deep pool of lighter liquid is investigated using three-dimensional numerical simulations. Unprecedented to any numerical simulations, we demonstrate that the heavier droplets can hang from the surface of a lighter liquid using surface tension. The impact phenomenon and the evolution of the heavier droplet as a function of its size and release height are explored. A theoretical model is also formulated to understand the role of different forms of energies associated with the hanging droplet. We further solve the force balance equations for the hanging droplets analytically and demonstrate that the results obtained from our simulations match very well with the analytical solution. This research offers opportunities in many areas, including drug and gene delivery, encapsulation of biomolecules, microfluidics, soft robots, and remediation of oil spills.