Structural optimization and characteristics analysis of innovative flapper shape in a flapper-nozzle pilot valve

Cavitation in the flow field and the resonance of armature-flapper assembly are two main possible mechanisms for the self-excited noise in flapper-nozzle pilot valves, which can greatly deteriorate the performance of the valves. In our previous attempt, it has been shown that compared to traditional flapper shape, rectangle-shaped flapper is more effective to reduce cavitation in the flapper-nozzle pilot valve. However, it is necessarily important to obtain the same structural properties as traditional flapper shape. To achieve this aim, structural optimization of the innovative flapper shape is performed. Then, the static and dynamic characteristics of the armature-flapper assembly using different flapper shapes are studied numerically using a validated numerical model. The simulated static and dynamic characteristics of the optimized innovative flapper shape agree well with that of the traditional one. Thus, an effective flapper shape which can reduce cavitation as well as maintain the original mechanical performances is proposed.