Investigation of Slip Condition in the Elastohydrodynamic Lubrication

Document Type : Original Article

Authors

• Javad Sharifi Yalameh ¹
• Amir Torabi ²

¹ Faculty of Engineering and Technology, Shahrekord University, Shahrekord, Iran.

² ّFaculty of Engineering and Technology, Shahrekord university, Shahrekord, Iran.

10.22067/jacsm.2024.84427.1203

Abstract

The non-slip condition is one of the acknowledged conditions in the common fluid dynamic applications. In some specific cases, this assumption is challenged. When high speed and pressure occur in a part of the flow near the surface, such as in the lubrication of non-conformal surfaces, there is a possibility of slippage on the surface. In this study, the effect of fluid slipping on the surface in elastohydrodynamic lubrication has been numerically investigated. A numerical model was derived based on the equations governing the flow of the lubricating fluid and with the assumption that the fluid is Newtonian and the flow is isothermal. The geometry includes an upper long cylindrical surface and a lower flat surface. The equations were discretized by the finite difference method and solved by the least squares method. In this investigation, in addition to proving the existence of slip, its effect was considered for various values of problem parameters, such as the speed of the surfaces, load, the ratio of the speed of the surfaces, and the limit shear stress. The results showed that with the increase in speed and load, a significant slip occurs and the no-slip condition causes a deviation of 20% till 90% in the estimation of the friction coefficient. At the speed ratio near one, the slippage is higher. As the shear stress increases, the occurrence of sliding becomes more limited. Slipping reduces the friction of lubrication.

Keywords

• Lubrication
• Elastohydrodynamic
• Slip condition
• Friction
• Modeling
• Reynolds equation

Main Subjects

• Fluid mechanics

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