Universality of stretching separation

TL;DR

This paper presents a universal, parameter-free model for drop collision fragmentation, linking stretching separation to a critical aspect ratio and extending the approach to drop-jet collisions with similar fragmentation criteria.

Contribution

It introduces a universal model for fragmentation in off-center drop collisions, incorporating viscosity effects and extending to drop-jet interactions with a unified criterion.

Findings

Excellent prediction across various liquid properties

Stretching separation occurs at a critical aspect ratio of 3.25

Model applies to both drop-drop and drop-jet collisions

Abstract

We develop a parameter-free model for the fragmentation of drops colliding off-center. The prediction is excellent over a wide range of liquid properties. The so-called stretching separation is attributed to the extension of the merged drop above a critical aspect ratio of {3.25}. The evolution of this aspect ratio {is influenced by the liquid viscosity} and can be interpreted via an energy balance. This approach is then adapted to drop-jet collisions, which we model as consecutive drop-drop collisions. {The fragmentation criterion is similar the one observed at drop-drop collisions}, while the evolution of the stretched jet aspect ratio is modified to account for the different flow fields and geometry.