Transient Behavior of a Cavitating Centrifugal Pump at Rapid Change in Operating Conditions—Part 1: Transient Phenomena at Opening/Closure of Discharge Valve

Abstract

A series of studies on the dynamic characteristics of noncavitating centrifugal pumps were extended to the cavitating case. An experimental study was carried out on the transient behavior of a cavitating centrifugal pump at the sudden opening/closure of the discharge valve. Cavitation behavior in the centrifugal pump was visualized during the transient period by using high speed video camera, and instantaneous pressure and flowrate were measured at the pump suction and discharge section with rotational speed during the transient period. Unsteady pressure, as well as flowrate, was related to the time-dependent cavitation behavior. As a result of the present study, pressure and flowrate fluctuations were found to occur due to oscillating cavitation or water column separation at rapid transient operations.