INSTABILITY OF FREE-SURFACE FLOWS ABOVE PAIR VORTICES

Abstract

 In this study, interactions between free-surface and a sub-surface vorttex pair have been numerically investigated with the aim to understand evolution of vortices under breaking waves. Three dimensional Large Eddy Simulation has been performed in numerical water tank with analytical vortex pairs as an initial condition. When the vortices vertically translated by self-induction approached a still water surface, the surface was lifted above the vortices owing to vortex-induced flow. Additional small scale vortices were produced on the resulting surface defomation with high curvature, resulting in small scale surface fluctuations.