Surface tension as the destabiliser of a vortical interface

We study the dynamics of an initially flat interface between two immiscible fluids, with a vortex situated on it. show how surface tension causes vorticity generation at general curved interface. This creates velocity jump across which increases quadratically in time, and Kelvin–Helmholtz instability. Surface thus acts as destabiliser by creation, winning over its own tendency to stabilise smoothing out interfacial perturbations reduce energy. further that this instability is manifested within core times larger than ${\sim}(k We)^{1/4}$ for Weber number $We$ perturbation wavenumber $k$ , destroying flow structure. The peels off into small-scale structures away from Using energy balance we provide growth total length time. A density difference fluids produces additional instabilities outside due centrifugal effects. demonstrate importance mechanism two-dimensional turbulence simulations prescribed initial