Thermodynamic Effects on Cavitation Performances and Cavitation Instabilities in an Inducer

Abstract

In the present study, we focused on the length of the tip cavitation as a cavitation parameter for experimental investigations of the thermodynamic effect on a cavitating inducer. Comparison of the length of tip cavity in liquid nitrogen (76 K and 80 K) with that in cold water (296 K) allowed us to estimate the strength of the thermodynamic effect. In addition, unstable cavitation phenomena occur when the cavity length develops over the throat. Sub-synchronous rotating cavitation appears both in liquid nitrogen and in cold water. In contrast, cavitation surge appears only in cold water at a lower cavitation number. From these experimental results, thermodynamic effects on cavitation performances and cavitation instabilities were discussed.