Effect of non-newtonian lubricants on static and dynamic characteristics of journal bearings

Journal bearings play a significant role to increase overall level of reliability in machines. Advancements in lubrication methodology have a great impact on the performance of journal bearings which operate under multifarious parameters and lubrication conditions. Bearing behaviour is monitored by bringing out changes in various aspects like geometry, misalignment value, restrictor design parameter, restrictor types, eccentricity, roughness, aspect ratio, lubricant feeding conditions and lubricating oil properties. Performance of bearings is tremendously dependent on the variation in lubricant properties. This paper presents the state-of-the-art review on the behaviour of lubricants, namely, micropolar, power-law fluids and couple stress lubricants and their effects on journal bearings efficiency. An effort is made to understand the behaviour of different non-Newtonian lubricants on various journal bearing configurations and their comparison with Newtonian lubricants so as to choose the appropriate lubricant for specific bearing configuration. Non- Newtonian lubricants have shown improvements in journal bearing performance when compared with Newtonian lubricants operating at selected conditions. (C) 2020 Elsevier Ltd. All rights reserved.