1. Cavitation effects

Cavitation is the vaporization of a fluid at a pressure below its vapor pressure. This phenomenon is manifested by the formation of bubbles, pockets, vortices or steam torches within the flow. In pumps, these steam structures appear in low-pressure zones at the impeller blade inlet, and are transported to higher-pressure zones. Under the action of the pressure gradient, they implode as soon as the local pressure in the flow becomes higher than the steam pressure. These implosions produce microjets and overpressures (shock waves) that can reach hundreds or even thousands of bar.