Stability Analysis of Cavitation Surge in Hydraulic System Considering Response Delay of Cavitating Pump

Abstract

Cavitation surge is a system instability caused by mutual interference between cavitation and a hydraulic system. A stability analysis for the cavitation surge was performed based on the unsteady characteristics of the cavitating pump, that is, the response delay of the pressure rise against the suction and discharge flow and suction pressure oscillations. Ordinary differential equations were derived from linear unsteady momentum and continuity equations, and the simplified-derived ordinary differential equations clearly show the onset criteria of stability and dynamic instabilities. The relatively short discharge and large suction pipe loss had a stabilizing effect on the cavitation surge. The positive quasi-steady suction and discharge flow gains as well as the negative quasi-steady suction pressure gain cause surge instability. The phase advance of the pressure rise against the flow and pressure oscillations also leads to surge instability.