A Study of Misaligned Micropolar Lubricated Membrane Compensated Hybrid Journal Bearing System

Abstract

The present work aims to analytically study the performance of misaligned four-pocket, membrane compensated, hybrid journal bearing system operating with micropolar lubricant. In the present study, the flow characteristic of the lubricating oil containing additives and contaminants has been modeled using Erigen’s micropolar theory. The journal misalignment which may occur as a result of noncentral loading, improper assembly, shaft deflection due to elasticity and thermal distortions, etc. has been accounted for in the present study by defining a pair of misalignment parameters in vertical and horizontal directions (i.e., δ and σ).The modified Reynolds equation governing the flow of micropolar lubricant in the clearance space of a misaligned bearing has been solved using FEM and Newton Raphson method along with the appropriate boundary conditions. The numerically simulated results suggest that the effect of journal misalignment is to cause degradation in bearing performance, whereas the influence of micropolar effect of lubricant is to enhance the bearing performance. Therefore, it is imperative to account for the effect of misalignment and lubricant behavior during the design process in order to generate accurate bearing characteristics data.