Abstract
The aim of our study is to suppress cavitation near the flange of an actual poppet valve by changing the shape of the flange. The experimental flow visualization technique and numerical flow analysis using the vortex method and boundary element method are employed to achieve the purpose. In the flow visualization, cavitation phenomenon near the flange is observed using an industrial fiber scope inside an actual balanced piston type relief valve which is used in oil hydraulic systems. On the other hand, in the flow analysis, the two dimensional vortex method and boundary element method are applied to estimate cavitation near the flange. Ten types of poppets are designed by changing the shape of the flange, which is expected to influence the jet flow issuing from the orifice. In conclusion, the physical region of cavitation and the cavitation region of the Reynolds number-cavitation number plane are small for an optimal poppet geometry obtained in the present study.
