Study of Cavitation Bubbles Evolution for High-Speed Water-Lubricated Spiral Groove Thrust Bearings

Abstract

The purpose of this study is to investigate the evolution of cavitation bubbles for the high-speed water-lubricated spiral groove thrust bearing. A theoretical model of cavitation bubble evolution considering multiple effects (interface, breakage, and coalescence of bubbles) was established for the bearing. A high-speed experimental setup was developed to measure the distribution of bubbles. The theoretical model is verified by the experimental data. The results show that the Boltzmann-type bubble transport equation can be used to describe the bubble evolution of the bearing under the breakup and coalescence at high-speed conditions; the volume of the bubble group presents a skewed distribution in equilibrium; the number of small-sized bubbles is greater than that of large-sized bubbles at high rotational speed; the bubbles are mainly distributed at the inlets and outlets of spiral grooves; the bubble number density increases with the groove depth and spiral angle; more bubbles are generated near the outer diameter of the bearing. The study provides a theoretical and experimental basis for the bubble evolution of the water-lubricated spiral groove bearing under high speeds.