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.

Investigations of the three-dimensional temperature field of journal bearings considering conjugate heat transfer and cavitation

“…Combining the Reynolds equation with the energy equation and heat conduction equation, a thermo-hydrodynamic lubrication (THD) model of journal bearings was established (Han and Paranjpe, 1990;Paranjpe and Han, 1994;Singh et al, 2008;van Ostayen and van Beek, 2009;Chauhan et al, 2011;Singla and Chauhan, 2016;Chen et al, 2017). However, the inertia effect, which is ignored by the Reynolds equation, has a considerable effect on the temperature and pressure distribution of the oil film (Nassab, 2005;. Recently, with the rapid development of computer technology and hardware, many researchers used computational fluid dynamics (CFD) programs in their investigations of hydrodynamic lubrication (Guo et al, 2005;Gao et al, 2014).…”

Study and Advance on High Speed Machine Tool Sleeve Bearing with Low Viscosity Lubrication

“…Bouyer et al [23] tested the journal misalignment effects on hydrodynamic plain journal bearing performances by experiment. Nassab et al [24] studied the inertia effect on the thermohydrodynamic characteristics of journal bearings.…”

Effect of fluid inertia force on thermal elastohydrodynamic lubrication of elliptic contact

“…As is well known, the usual Reynolds equation is derived from the Navier-Stokes equations with several simplified assumptions including negligible inertia force of the lubricant. This dealing is theoretically acceptable in the hydrodynamic lubrication analysis for the mechanical component operating at small values of Reynolds number of the lubricant [1]. Based on this assumption, the Newtonian or non-Newtonian thermal elastohydrodynamic lubrication (EHL) performances of point contacts such as ball bearings have been extensively studied theoretically and experimentally in the past years.…”