Study of Dynamic Characteristics of Water-Lubricated Journal Bearings Using Thermohydrodynamic Cavitating Lubrication Model

Abstract

Cavitation is prone to occur in high-speed water-lubricated journal bearings. However, the effect of cavitation on the dynamic characteristics of high-speed water-lubricated journal bearings has not been studied thoroughly. This study focuses on this topic. A thermohydrodynamic (THD) cavitating lubrication model was established for the high-speed water-lubricated journal bearings, including the generalized Reynolds equation, the energy equation, and the force balance equation for bubbles. An equilibrium distribution was introduced to describe the cavitation effect, and parameters were obtained by fitting the measured volume distribution of bubbles. The dynamic characteristics of the water-lubricated journal bearings were calculated, considering the influence of thermal and cavitation effects. An experimental setup was developed to validate the proposed model. The simulated results show that two secondary temperature peaks appear in the divergence zone of the bearing due to the cavitation effect. The cavitation effect should be considered when establishing the model for high-speed water-lubricated journal bearings, especially if it is under a large eccentricity ratio.