Experimental Studies on the Pressure Fluctuations in a Cavitating Pipe-Flow

Abstract

This paper presents experimental studies of pressure fluctuations in a cavitating pipe-flow. Using a high speed cinecamera, the behavior of the cavity which grows and collapses after the throat of a sharp-edged venturi was photographed and analysed. The cavity is periodically cut off at the throat, swept down and collapsed rapidly at a certain distance from the throat. After the collapse the fluid around the cavity is accelerated and pressure waves are generated, which then excite the fluid column into oscillation. The cavity shedding frequency becomes lower (less than 100 Hz) with increase in the average cavity length and resonance phenomena occur when it coincides with one of the natural frequencies of the fluid column.