ANALYSIS OF SOME CHARACTERISTICS OF HYDRAULIC CONTROL VALVES USING A STREAMLINE COORDINATE METHOD

Abstract

In order to improve the characteristics of a control valve, it is necessary to precisely predict the flow inside. Under these Circumstances a method using so called streamline coordinates has been developed. In this method, one of the coordinates is chosen along a streamline, and the other coordinate orthogonal with streamlines. A control valve has several restrictions, and the flows through them form flow jets with free discontinuous surfaces. The streamline-coordinate method can solve such a problem, since a free surface consists of streamlines. The important characteristics of a hydraulic control valve include the flow coefficient at its metering orifice and axial forces acting on the valve body. These characteristics can be numerically predicted using the streamline-coordinate method. Those characteristics of poppet and spool valves are analyzed by the streamline-coordinate method, and the usefulness of this method is shown.