CFD analysis of nano-lubricated journal bearing considering variable viscosity and elasticity effects

Abstract

The main Objective of the present work is to study the behavior of nano lubricated journal bearing considering elasticity and variable viscosity effects. A mathematical model for a journal bearing was employed using three-dimensional computational fluid dynamics. The study was implemented for a journal bearing with laminar flow and smooth surfaces lubricated with pure oil as well as lubricants containing different concentrations of Al2O3 Nano-particles. The dependence of the oil viscosity on the temperature was considered by using modified Krieger Dougherty model. Pressure, temperature and elastic deformation in addition to the bearing load carrying capacity of the bearing working under different eccentricity ratios (0.1-0.6) have been studied. The mathematical model was confirmed by comparing the results of the pressure and temperature distributions obtained in the current work with those obtained by Ferron et al.(1983) for a bearing lubricated with pure oil. Also, the pressure obtained for nanolubricated bearing of the present work was validated with that obtained by Solighar (2015). The results are found in a good agreement with maximum deviation not exceed 5%. The obtained results show that the oil film pressure increases by about 17.9% with slight decrease in oil film temperature and friction coefficient.

Keywords

• thermal effect
• hydrodynamic lubrication
• elastic deformation
• nano-lubricant
• variable viscosity