Entrainment of Air Bubbles During Strong Vorticity-Free-Surface Interaction

The air entraiment induced by vorticity-free-surface interaction is here numerically investigated using a two-fluid model which describes the flow in air and water as that of a single incompressible fluid whose density and viscosity vary smoothly across the interface. The numerical approach is used for the simulation of a viscous vortex pair vertically rising toward the free surface. Several flow conditions are studied aimed at understanding the role played by vortex intensity, surface tension and gravity forces on the amount of entrained air and the mechanisms forits entrainment.