抄録
A hydraulic holding valve of the poppet type has been modified and improved in order to prevent the occurrence of cavitation and reduce cavitation noise near the orifice. The ways in which cavitation occur are investigated by visually observing the flow using half-cut models of the valves in case of converging flow. Test facilities were designed to control the flow rate, upstream pressure, downstream pressure, and valve lift. Moreover, good results regarding noise reduction could be obtained by noise measurements of the half-cut models of the improved valve. Especially, with respect to the relation between the forms of occurrence of the cavitation and noise level, the detailed studies were undertaken by changing Reynolds number and cavitation number.
