Influence of micropolar lubricant on bearings performance: A review

This article presents the applicability of the microcontinuum theories to the fluid in sliding surfaces. The classical continuum mechanics fails to predict the accurate results when the geometric volume under consideration becomes comparable to the material dimensions. The fluid in the presence of microstructures and in the space comparable to the clearance of bearings showed unexpected variations in its properties as per the experimental observations. A general class of micropolar fluid was defined by considering the microrotation vector of its particles. This review critically analyzes the microrotation of lubricant additives and its effects on static and dynamic characteristics of the bearings.