A Visual Observation of Cavitating Inducer Instability

Abstract

This paper presents the results of experiments on the instability of a cavitating inducer, which is considered to be closely related with the POGO phenomena in liquid propellant rockets. The present experiment employed a high speed camera for visual observations. The dynamic pressure of both the inducer upstream and downstream was also measured.The difference between rotating cavitation and cavitation induced low cycle oscillations was examined. In rotating cavitation, the cavities moved around the periphery of the inducer inlet with a constant rotating speed. All cavities oscillated almost in unison in the case of the cavitation induced low cycle oscillation.