Study on the flow field and steady-state hydrodynamics of a sliding valve with a sloping U-shaped throttle groove

Abstract

Existing U-shaped throttle grooves in spool valves face issues such as unstable fluid flow, high-pressure drop, and uneven variation of flow area. This paper proposes a novel spool valve throttle groove featuring a sloped U-shaped configuration. Through theoretical derivation of mathematical models for flow areas of different throttle grooves combined with CFD simulation analysis of flow field characteristics and distribution patterns, the study reveals the influence of flow area change gradient on hydrodynamic forces. Furthermore, three-dimensional hydraulic spool valve models with different throttle grooves were established to analyze the effects of key parameters - valve opening (1 mm, 3 mm, 5 mm), pressure difference (1 MPa, 3 MPa, 5 MPa), and slope angle (6°, 12°, 18°) - on flow field characteristics and hydrodynamic behavior. Results demonstrate that the sloped U-shaped throttle groove exhibits more stable pressure and velocity distributions under varying openings and pressure differences, significantly reducing hydrodynamic force fluctuations with a maximum reduction of 59.72 %, thereby improving system stability and flow control accuracy. Experimental validation using a comprehensive hydraulic valve test bench confirmed the accuracy of the spool valve simulation model. The research indicates that the sloped U-shaped throttle groove effectively enhances spool valve system stability, extends component lifespan, and improves hydraulic control precision, providing theoretical support for designing and optimizing hydraulic spool valves.