Reducing the steady flow force acting on the spool by using a simple jet-guiding groove

Reducing the flow induced forces acting on the spool is necessarily important for the energy efficient operation and minimizing the stability problem in different types of spool valves. Aiming to reduce the steady flow force acting on the spool, a simple jet-guiding groove is proposed. It is V-groove created on the side face of the spool land. By means of Computational Fluid Dynamics (CFD) simulations, the effectiveness of proposed jet-guiding groove is analyzed at various spool strokes and depths of the groove. The port width to spool stroke ratio is varied in the range of 0.1–0.5. The ratio of land face depth to groove depth is varied as 0.125, 0.25, 0.5 and 1. The results show that compared to the traditional spool, the spool with jet-guiding groove can proportionally reduce the steady flow force at every spool stroke. The deeper the depth, the more effective the jet-guiding groove in reducing flow force. Providing the same flow control capability as the traditional spool and other multiple advantages, the spool with jet-guiding groove can reduce the power requirement in operation.