Laser-induced cavitation bubble collapsing in the vicinity of the leading edge of a hydrofoil

In the present study, a high energy pulsed laser is used to generate a millimetric cavitation bubble within a water flow over a symmetric hydrofoil. The bubble is initiated at different locations in the vicinity of the hydrofoil leading edge. A high-speed camera is used to observe the motion and the deformation of the bubble as it travels along the hydrofoil suction side. We have found that the pressure gradient plays a major role on the bubble dynamic and subsequent phenomena. For a specific region of the flow, the micro-jet initiated at the collapse of the bubble is no more directed towards the hydrofoil surface, as commonly observed in still water. In this case, we also observe a spectacular behaviour of the cavity rebound, which migrates towards the solid surface despite of the outward direction of the micro-jet.