A study of flow-field distribution between the flapper and nozzle in a hydraulic servo-valve

This study is aiming to give understanding of flow field distribution in the pilot stage of a flapper-nozzle hydraulic servo-valve and to study the characteristics between the flow rate and the pressure drop over the nozzle. After introducing the construction and working principle of the hydraulic servo valve, the mathematical models for the flow field simulation based on standard k-∊ model for turbulent flow are built. The simulation results show the velocity flow field distribution at different conditions. The characteristics between the flow rate of the pilot stage and the pressure drop over the nozzle are also given by simulation. The simulation results provide theoretical basis for the design and understanding of flow field distribution in the pilot stage of a flapper-nozzle hydraulic servo-valve.