Performance characteristics of two-lobe pressure dam bearings with micropolar lubrication

Abstract

A circular bearing experiences the instability problem due to oil whirl, causing violent vibrations at high speed. Two-lobe pressure dam bearing is a solution to the instability arising in high-speed rotating machineries. The paper presents the various static and dynamic characteristics of two-lobe pressure dam bearings, while operating with micropolar fluid. The modified Reynolds equation used to model the lubrication is solved using the finite element method. Performance characteristics such as load, attitude angle, critical mass, threshold speed and whirl frequency are computed, presented graphically and analysed. A detailed comparison of the performance characteristics is done for various micropolar and dam parameters. It is concluded that bearing performance is significantly influenced by dam parameters (dam angles) and micropolar parameters (coupling number and characteristics length).