Cavitation characteristics and suppression of pilot stage two-dimensional valve

Abstract

The two-dimensional (2D) valve integrates the spool pilot and power stages to realize the valve's fast operation and high-frequency response. It has the advantages of simple structure, stable performance, and large power-to-weight ratio. In this paper, the cavitation flow in the pilot stage of the 2D valve is analyzed utilizing computational fluid dynamics. The effects of inlet and outlet pressure difference, outlet pressure, and valve opening velocity on cavitation are studied, and a U-shaped groove structure is designed to restrain cavitation. The results demonstrate that the greater the pressure difference, the higher is the cavitation intensity. Furthermore, the cavitation intensity increases with decrease in outlet pressure. The cavitation phenomenon occurs in the 2D valve pilot stage when the valve opening speed is high, and there is no cavitation in the flow channel with the decrease of the valve opening speed. After U-shaped grooves are opened on both sides of the valve sleeve groove, the cavitation number in the 2D valve pilot stage increases significantly compared with the original inclined groove structure under the same pressure difference. Additionally, the effect of restraining cavitation is pronounced with the increase of the width–depth ratio of U-shaped grooves, and the cavitation number increases.