Effect of Viscosity Variation on the Micropolar Fluid Squeeze Film Lubrication of a Short Journal Bearing

N B Naduvinamani,Archana K Kadadi

doi:10.1155/2013/743987

Abstract

A theoretical study of the effect of the viscosity variation on the squeeze film performance of a short journal bearing operating with micropolar fluid is presented. The modified Reynolds equation accounting for the viscosity variation in micropolar fluid is mathematically derived. To obtain a closed form solution, the short bearing approximation under constant load is considered. The modified Reynolds equation is solved for the fluid film pressure and then the bearing characteristics, such as obtaining the load carrying capacity and the squeeze film time. According to the results evaluated, the micropolar fluid as a lubricant improves the squeeze film characteristics and results in a longer bearing life, whereas the viscosity variation factor decreases the load carrying capacity and squeezes film time. The result is compared with the corresponding Newtonian case.

Highlights

The application of squeeze film action is commonly seen in gyroscopes, gears, aircraft engines, automotive engines, and the mechanics of synovial joints in human being and animals
Because of the viscous lubricant present between the two surfaces, it takes certain time for these to come into contact
Since the viscous lubricant has a resistance to extrusion, a pressure is built up during that interval, and the lubricant film supports the load

Summary

Introduction

The application of squeeze film action is commonly seen in gyroscopes, gears, aircraft engines, automotive engines, and the mechanics of synovial joints in human being and animals. Several researchers [2,3,4,5,6,7,8,9,10] have studied the performance of different bearing systems lubricated with micropolar fluids and reported the advantages of these lubricants over Newtonian case such as increased load carrying capacity, lower coefficient of friction, and delayed time of approach All these studies are based on the assumption that the viscosity is constant. In the present paper, an attempt has been made to analyse the effects of variation of viscosity on the squeeze film lubrication of journal bearings lubricated with micropolar fluids.

Solution of the Problem

Findings

Result and Discussion

Conclusions