Vortex Cavitation

Vortices are important for ship propellers because the pressure in the core is low and thus cavitation may occur. Vortex cavitation is not erosive when it is not excessive, but it is a source of noise. And noise is used to detect ships and is thus important for navy ships.Radiated noise was and is used to nd the location of ships. Since low frequency noise reaches longer distances these frequencies were detected with towed arrays. This detection method has been replaced by detection by satellites. However, for close range detection noise is still very important, because the main target of torpedoes is a noise source. Tip vortex inception often determines the speed at which the propeller starts to radiate cavitation noise, which remains important for navy ships.