Three dimensional CFD analysis and experimental test of flow force acting on the spool of solenoid operated directional control valve

Solenoid direct operated spool type directional control valves are often used in various machines and equipment. A subject of the analysis presented in the paper is the directional control valve WE10H produced by several manufacturers. The continual development of this type of valves has allowed for significant reduction of the flow resistance through the channels and consequently for relatively high flow range. The increase of flow range causes a growth of flow forces which may change the balance of forces acting on the spool and prevent the correct operation of the valve. That is why the undertaken task is important. The paper proposes calculation of the forces associated with the flow (pressure force and viscous force) using 3D CFD modeling. In the proposed method, first the surface affected by the forces associated with the flow through each path was defined and then, using CFD method, values of the flow forces were determined. To confirm the obtained results of CFD calculations a device for measuring forces acting along the axis of the spool was prepared. The force values obtained in the CFD calculations were compared with those obtained on the test bench. The resulting accuracy was satisfactory. In order to reduce flow forces additional internal channels in the valve body were introduced. The innovative solution of the valve allowed for a higher flow range of about 45% without any change of spring or solenoid. (C) 2013 Elsevier Ltd. All rights reserved.