Instabilities in charged tori

Abstract

This report aims to shed light on the different instability regimes of charged toroidal droplets. Firstly, we have studied the shrinkage and breakup of neutral tori through Rayleigh-Plateau instabilities. When charged, electrical stresses can overcome surface tension stresses leading to droplet expansion. At even higher voltage, tori can develop Saffman-Taylor instabilities, which result in viscous fingering. Remarkably, at high enough potential, these viscous fingering branch out, giving rise to a magnificent dendritic-growth behaviour