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Z. Naturforsch. 67a, 412 – 418
(2012)
doi:10.5560/ZNA.2012-0035
Effects of Surface Roughness and Surface Force on the Thin Film Elastohydrodynamic Lubrication of Circular Contacts
1 Department of Mechanical and Automation Engineering, I-Shou University, Kaohsiung City 84001, Taiwan, R.O.C.
2 Department of Mechanical Engineering, Taoyuan Innovation Institute of Technology, Jhongli City, Taoyuan County 320, Taiwan, R.O.C.
Received November 16, 2011 / revised February 6, 2012 / published online July 3, 2012
Reprint requests to: L.-M. C.; Tel: 886-7-6577711ext3232, Fax: 886-7-6578853, E-mail:
hmchu@mail.isu.edu.tw
The effects of surface roughness and surface force on thin film elastohydrodynamic lubrication (TFEHL) circular contact problems are analyzed and discussed under constant load condition. The multi-level multi-integration (MLMI) algorithm and the Gauss–Seidel iterative method are used to simultaneously solve the average Reynolds type equation, surface force equations, the load balance equation, the rheology equations, and the elastic deformation equation. The simulation results reveal that the difference between the TFEHL model and the traditional EHL model increase with decreasing film thickness. The effects of surface forces become significant as the film thickness becomes thinner. The surface forces have obvious effects in the Hertzian contact region. The oscillation phenomena in pressure and film thickness come mainly from the action of solvation forces.
Key words: Thin Film Elastohydrodynamic Lubrication (TFEHL); Roughness; Surface Force.