Elastohydrodynamic lubrication of circular contacts at pure squeeze motion with micropolar lubricants

• Published in: Industrial lubrication and tribology Vol. 68; no. 6; pp. 640 - 646
• Main Authors: Chu, Li Ming, Lin, Jaw-Ren, Chang, Yuh-Ping, Wu, Chung-Chun
• Format: Journal Article
• Language: English
• Published: Bradford Emerald Group Publishing Limited 12.09.2016
• Subjects: Boundary conditions; Circularity; Computational fluid dynamics; Computer simulation; Conflicts of interest; Deformation; Design modifications; Elastic deformation; Elasticity; Elastohydrodynamic lubrication; Film thickness; Finite difference method; Fluids; Iterative methods; Journal bearings; Load; Lubricants; Lubricants & lubrication; Lubrication; Mathematical models; Micropolar fluids; Newtonian fluids; Numerical methods; Polar coordinates; Pressure distribution; Reynolds equation; Rheological properties; Rheology; Theory; Velocity; Viscosity; Lubrication; Tribology; Elastohydrodynamic lubrication; Micropolar lubricants
• ISSN: 0036-8792; 1758-5775
• DOI: 10.1108/ILT-10-2015-0139

Purpose This paper aims to explore pure squeeze elastohydrodynamic lubrication (EHL) motion of circular contacts with micropolar lubricants under constant load. The proposed model can reasonably calculate the pressure distributions, film thicknesses and normal squeeze velocities during the pure squeeze process. Design/methodology/approach The transient modified Reynolds equation is derived in polar coordinates using micropolar fluids theory. The finite difference method and the Gauss–Seidel iteration method are used to solve the transient modified Reynolds equation, the elasticity deformation equation, load balance equation and lubricant rheology equations simultaneously. Findings The simulation results reveal that the effect of the micropolar lubricant is equivalent to enhancing the lubricant viscosity. As the film thickness is enlarged, the central pressure and film thickness for micropolar lubricants are larger than those of Newtonian fluids under the same load in the elastic deformation stage. The greater the coupling parameter (N), the greater the maximum central pressure. However, the smaller the characteristic length (L), the greater the maximum central pressure. The time needed to achieve maximum central pressure increases with increasing N and L. Originality/value A numerical method for general applications was developed to investigate the effects of the micropolar lubricants at pure squeeze EHL motion of circular contacts under constant load.