Cavitation in a spool valve for water hydraulics

Cavitation sometimes occurs serious problems in hydraulic system. The problems become especially obvious in water hydraulic system because of higher saturated vapor pressure of water comparing of that of oil. This study is focused on cavitation phenomenon in a spool valve for Aqua Drive System. A spool valve model was made of transparent acrylic resin for visualization of cavitation phenomenon. Vibration and noise from the model were measured with changing the cavitation number. As a result, the vibration and noise are enhanced for the smaller cavitation number and the larger opening gap of a control port. It is, however, noticed that vibration and noise become large for some specific condition regardless of large cavitation number. It is revealed that these phenomena depend on cavitation type from visualization results.