Cavitation

Summary

Cavitation is the formation of vapour cavities in a liquid where the local pressure drops below the vapour pressure. The cavities collapse later when the pressure rises again. It occurs near fast propellers, in pumps, in valves and in strong sound fields. The collapse of the cavities is violent and can erode metal surfaces, make noise and reduce the efficiency of machines. The dynamics of a single cavity is modelled by the Rayleigh–Plesset equation.