Capillary Breakup of a Liquid Bridge: Identifying Regimes and Transitions

TL;DR

This paper uses advanced numerical simulations to map out different breakup regimes of a liquid bridge, revealing new transition behaviors and a recently discovered viscous regime, thus enhancing understanding of fluid breakup dynamics.

Contribution

It introduces a multiscale finite element method to accurately resolve the breakup process over four orders of magnitude, identifying new regimes and transition features in liquid bridge breakup.

Findings

Identification of a new low-Oh viscous regime

Observation of oscillatory convergence towards similarity solutions

Construction of a comprehensive phase diagram for breakup regimes

Abstract

Computations of the breakup of a liquid bridge are used to establish the limits of applicability of similarity solutions derived for different breakup regimes. These regimes are based on particular viscous-inertial balances, that is different limits of the Ohnesorge number $Oh$. To accurately establish the transitions between regimes, the minimum bridge radius is resolved through four orders of magnitude using a purpose-built multiscale finite element method. This allows us to construct a quantitative phase diagram for the breakup phenomenon which includes the appearance of a recently discovered low-$Oh$ viscous regime. The method used to quantify the accuracy of the similarity solutions allows us to identify a number of previously unobserved features of the breakup, most notably an oscillatory convergence towards the viscous-inertial similarity solution. Finally, we discuss how the new findings open up a number of challenges for both theoretical and experimental analysis.