Inertia Effect on the Thermohydrodynamic Characteristics of Journal Bearings

Abstract

In this article, the effect of lubricant inertia on the thermohydrodynamic behaviour of journal bearings is studied. Many researchers have analysed the inertia effect on lubricant flow in bearings using different simplifying assumptions. The purpose of this study is to eliminate most of those assumptions, using computational fluid dynamics (CFD) techniques to solve the exact governing equations. The bearing has a finite length and operates under incompressible laminar flow and steady conditions. Numerical solutions of the full three-dimensional Navier-Stokes equations with and without inertia terms, coupled with the energy equation in the lubricant flow and the heat conduction equations in the bearing and the shaft are obtained. Cavitation effects are also considered using an appropriate three-dimensional cavitation model. In order to study the effect fluid inertia under several different conditions, solutions are obtained for different values of the eccentricity and radial clearance and also for different values of the rotational speed of the shaft. To validate the computational results, comparison with the experimental data of other investigators is made, and reasonable agreement is obtained.