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Rheological Characteristics for Thin Film Elastohydrodynamic Lubrication

Published online by Cambridge University Press:  05 May 2011

H.-M. Chu*
Affiliation:
Department of Mechanical Engineering, Yung-Ta Institute of Technology & Commerce, Ping-Tung, Taiwan 909, R.O.C.
R. T. Lee*
Affiliation:
Department of Mechanical and Electro-Mechanical Engineering, National Sun Yat-Sen University, Kaohsiung, Taiwan 804, R.O.C.
S. Y. Hu*
Affiliation:
Department of Marine Engineering, National Kaohsiung Marine University, Kaohsiung, Taiwan 811, R.O.C.
Y.-P. Chang*
Affiliation:
Department of Mechanical Engineering, Kun Shan University of Technology, Tainan, Taiwan 710, R.O.C.
*
*Assistant Professor
**Professor
***Associate Professor
*Assistant Professor
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Abstract

This paper uses three lubrication models to explore the differential phenomenon in the status of thin film lubrication (TFL). According to the viscous adsorption theory, the modified Reynolds equation for thin film elastohydrodynamic lubrication (TFEHL) is derived. In this theory, the film thickness between lubricated surfaces is simplified as three fixed layers across the film, and the viscosity and density of the lubricant vary with pressure in each layer. Under certain conditions, such as a rough or concentrated contact of a nominally flat surface, films may be of nanometer scale. The thin film elastohydrodynamic lubrication (EHL) analysis is performed on a surface forces (SF) model which includes van der waals and solvation forces. The results show that the proposed TFEHL model can reasonably calculate the film thickness and the average relative viscosity under thin film EHL. The adsorption layer thickness and the viscosity influence significantly the lubrication characteristics of the contact conjunction. The differences in pressure distribution and film shape between surface forces model and classical EHL model were obvious, especially in the Hertzian contact area. The solvation force has the greatest influence on pressure distribution.

Type
Articles
Copyright
Copyright © The Society of Theoretical and Applied Mechanics, R.O.C. 2005

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References

REFERENCES

1.Johnston, G. J., Wayte, R. and Spikes, H. A., “The Measurement and Study of very Thin Lubricant Films in Concentrated Contacts,” STLE, 34, pp. 187194 (1991).CrossRefGoogle Scholar
2.Guangteng, G. and Spikes, H. A., “Boundary Film Formation by Lubricant Base Fluids,” STLE, 39, pp. 448454 (1996).Google Scholar
3.Luo, Jianbin, Wen, , Shizhu, and Huang, , Pin, , “Thin Film Lubrication, Part I: Study on the Transition between EHL and Thin Film Lubrication using a Relative Optical Interference Intensity Technique,” Wear, 194, pp. 107115 (1996).CrossRefGoogle Scholar
4.Hartl, M., Krupka, I., Poliscuk, R., Liska, M., Molimard, J., Querry, M. and Vergne, P., “Thin Film Colorimetric Interferometry,” STLE, 44, pp. 270276 (2001).Google Scholar
5.Chan, D. Y. C. and Horn, R. G., “The Drainage of Thin Liquid Films between Solid Surfaces,” J. Chem. Phys., 83, pp. 53115324 (1985).CrossRefGoogle Scholar
6.Brown, S. and Scholz, C., “Closure of Random Elastic Surfaces in Contact,” Journal of Geophysical Research, 90(B7), pp. 55315545 (1985).CrossRefGoogle Scholar
7.Jang, Siyoul and Tichy, John, “Rheological Models for Thin Film EHL Contacts,” ASME J. of Tribology, 117, pp. 2228 (1995).CrossRefGoogle Scholar
8.Tichy, J. A., “Modeling of Thin Film Lubrication,” STLE, 38, pp. 108118 (1995).CrossRefGoogle Scholar
9.Tichy, J. A., “A Surface Layer Model for Thin Film Lubrication,” STLE, 38, pp. 577582 (1995).CrossRefGoogle Scholar
10.Tichy, J. A., “A Porous Media Model for Thin Film Lubrication,” ASME, J. of Tribology, 117, pp. 1621 (1995).Google Scholar
11.Sham, T. L. and Tichy, John, “A Scheme for Hybrid Molecular Dynamics/Finite Element Analysis of Thin Film Lubrication,” Wear, 207, pp. 100106 (1997).Google Scholar
12.Matsuoka, Hiroshige and Kato, Takahisa, “An Ultrathin Liquid Film Lubrication Theory-Calculation Method of Solvation Pressure and Its Application to the EHL Problem,” ASME J. of Tribology, 119, pp. 217226 (1997).CrossRefGoogle Scholar
13.Ornstein, L. S. and Zernike, F., “Accidental Deviations of Density and Opalescence at the Critical Point of a Single Substance,” Proceedings of the Royal Academy, Amsterdam, 17, pp. 793806 (1914).Google Scholar
14.Perram, J. W., “Hard Sphere Correlation Functions in the Percus-Yevick Approximation,” Molecular Physics, 30, pp. 15051509 (1975).CrossRefGoogle Scholar
15.Zhang, , Chaohui, , Luo, , Jianbin, and Wen, , Shizhu, , “A New Postulation of Viscosity and Its Application in Computation of Film Thickness in TFL,” ASME J. of Tribology, 124, pp. 811814 (2002).CrossRefGoogle Scholar
16.Qu, Qingwen, , Wang, , Mei, , Chai, , Shan, and Yao, ,Fusheng, , “Velocity Analysis for Layered Viscosity Model under Thin Film Lubrication,” Tribology International, 34, pp. 517521 (2001).Google Scholar
17.Qu, Qingwen, Hu, Yahong and Zhu, Jun, “An Adsorbent Layer Model for Thin Film Lubrication,” Wear, 221, pp. 914 (1998).Google Scholar
18.Nicholson, D. and Parsonage, N. G., Computer Simulation and the Statistical Mechanics of Adsorption, Academic Press (1982).Google Scholar
19.Israelachvili, J., Intermolecular and Surface Force, 2nd Edition, Academic Press (1991).Google Scholar
20.Dowson, D. and Higginson, G. R., Elastohydrodynamic Lubrication, Pergamon Press, pp. 8892 (1966).Google Scholar
21.Roelands, C. J. A., Vlugter, J. C. and Watermann, H. I., “The Viscosity Temperature Pressure Relationship of Lubricating Oils and Its Correlation with Chemical Constitution,” ASME Journal of Basic Engineering, pp. 601606 (1963).Google Scholar
22.Hsu, C. H. and Lee, R. T., “Advanced Multilevel Solution for Elastohydrodynamic Problem Circular Contact,” Wear, 177, pp. 117127 (1994).Google Scholar