METHOD OF DETERMINING CHARACTERISTICS OF NONDIMENSIONAL PARAMETERS OF WORKING LIQUID FLOWS IN VALVE CLEARANCES

摘要

FIELD: mechanical engineering; valve testing facilities. SUBSTANCE: invention relates to hydraulic equipment and it can be used in determining characteristics of non-dimensional parameters of liquid flows through valve clearances at designing and investigating different devices. According to proposed method, working liquid is delivered into supply channel of valve and is drained through outlet channel. At different values of relative back pressure maintained at valve clearance outlet and determined as ratio of drain pressure to delivery pressure, pressure differential across valve clearance is changed by steps. Said pressure differential is determined as difference between delivery pressure and drain pressure. Corresponding values of delivery pressure and drain pressure are provided. At each fixed value of pressure differential under steady conditions, flow rate of working liquid through valve clearance is determined. Preliminarily, before starting delivery of liquid, valve gate is set in position relative to housing corresponding to zero clearance. In process of testing, displacement of spring-loaded valve gate without tightening of spring is determined. Using transparent model of valve, angle of flow through valve clearance is found corresponding to said displacement, and area of through section of valve clearance is calculated depending of form size and value of displacement of valve gate. Then, using flow rate coefficient, flow compression coefficient and Raynolds number are found using proposed equations. EFFECT: possibility of determination of all non-dimensional parameters of working liquid flows in valve clearances. 1 dwg