A cavitation-induced bubbly sheet flows over the upper surface of a hydrofoil in the image above. Cavitation can occur when local pressure in a liquid drops below the vapor pressure, causing a cavity to form. Due to its angle of attack, water flowing over the upper surface of the hydrofoil is accelerated. The high flow velocities and accompanying low pressures over the top of the hydrofoil produce cavitation bubbles which continue to flow over and off the surface. Because cavitation bubbles implode when the pressure again increases, they can cause serious damage to solid surfaces. This is why generating cavitation can damage propellers or shatter a bottle. (Photo credit: R. Arndt et al.)
Celebrating the physics of all that flows