Contact line singularity triggers far field perturbations during bubble collapse*

The impulsive acceleration of an spherical cap in contact with a wall can show the presence of a singularity at the contact line for contact angles larger than 90 degrees. In this work we show that a laser induced shock wave can be used to experimentally investigate the consequences of this singularity during the  collapse of spherical cap bubbles. We observe high accelerations close to the wall and the formation of a rentrant jet parallel to the wall that, for high enough Reynolds and Weber numbers, leads to the formation of a vortex dipone propagating ouwards the wall. The resulting vortex is shown to be able to perturb the flow at long distances including the formation of jets at the free surface.