Some aspects of lubrication in heavy regimes: Thermal effects, stability and turbulence

Abstract

In this work, a combination of numerical methods applied to thermohydrodynamic lubrication problems with cavitation is presented. It should be emphasized the difficulty of the nonlinear mathematical coupled model involving a free boundary problem, but also the simplicity of the algorithms employed to solve it. So, finite element discretizations for the hydrodynamic and thermal equations combined with upwind techniques for the convection terms and duality methods for nonlinear features are proposed.Additionally, a model describing the movement of the shaft is provided. Considering the shaft as a rigid body this model will consist of an ODE system relating acceleration of the center of gravity and external and pressure loads. The numerical experiments of mechanical stability try to clarify the position of the neutral stability curve.Finally, a rotating machine for ship propulsion involving both axial and radial bearings operating with nonconventional lubricants (seawater to avoid environmental pollution) is analyzed by using laminar and turbulent inertial flows.

An extended Reynold equation applicable to high reduced Reynolds number operation of journal bearings

“…The ElrodAdam cavitation model is an alternative which satisfies the flow conservation in both pressure and cavitation regions and used in multiple studies [34,35,46]. Wang and Khonsari used Floberg-Jakobsson model to determine the inception of cavitation in two papers on long journal bearings [47,48].…”

“…Following Constantinescu and Galetuse [30], this numerical scheme was adopted by [32,33,34,35,36] and many others.…”

“…Constantinescu's approach in a thermohydrodynamic analysis and studied axial and radial bearings in ship propulsion machines operating in heavy regimes [34]. In a recent study, Durany et al verified the validity range of Constantinescu's two dimensional inertia and turbulence model against a 3D CFD analysis based on Large Eddy Simulation (LES) turbulence [35].…”

A Thermal Equilibrium Analysis of Line Contact Hydrodynamic Lubrication Considering the Influences of Reynolds Number, Load and Temperature

“…Gradually, some researchers [ 1 , 2 ] recognized the importance of including thermal effects in hydrodynamic lubrication analysis. In recent years, to achieve the higher lubrication and cooling demands of engineering design, research on thermal effects has become meaningful and important because of its great influence on lubrication performance [ 3 – 6 ].…”

The study of tilt effect on the preloaded oil pad of hydrostatic turntable

“…Furthermore, numeroushave paid attention to the various aspects of the characteristics of hydrostatic turntable or bearing [1][2][3][4][5][6][7][8][9][10][11][12][13] .According to references review, we found the investigation of tilt effect is not sufficient. The preloaded oil pad is an important part of the supporting systemof hydrostatic turntable.…”