A parametric analysis of the thermal shear localization in EHL films

Liming Chang

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Experiments and computer simulations [1] have revealed some unusual results of elastohydrodynamic lubrication (EHL) associated with a high degree of thermally induced inhomogeneous shear across the lubricant film, or thermal shear localization. The results include the development of a sizable film dimple in the central EHL region [2] and a dramatic reduction in EHL traction [3, 4]. In this study, a theoretical analysis is carried out to determine the conditions under which the thermal shear localization may develop in EHL films. For a Newtonian lubricant obeying the Barus law of viscosity, a dimensionless group-parameter is identified that fully governs the degree of the thermal inhomogeneous shear. Results are presented that show the critical range of values of this parameter corresponding to the onset of the shear localization. The analysis is also extended to lubricants with non-Newtonian behavior. Results suggest that the same dimensionless group-parameter may be used to measure the degree of the shear localization when the lubricant viscosity in the parameter is replaced by an effective viscosity that accounts for the non-Newtonian effect. Reference [5] presents details of the theoretical formulation and results analysis.

Original languageEnglish (US)
Title of host publicationProceedings of the World Tribology Congress III - 2005
Pages543-544
Number of pages2
StatePublished - 2005
Event2005 World Tribology Congress III - Washington, D.C., United States
Duration: Sep 12 2005Sep 16 2005

Other

Other2005 World Tribology Congress III
CountryUnited States
CityWashington, D.C.
Period9/12/059/16/05

Fingerprint

Elastohydrodynamic lubrication
Lubricants
Viscosity
Hot Temperature
Computer simulation
Experiments

All Science Journal Classification (ASJC) codes

  • Engineering(all)

Cite this

Chang, L. (2005). A parametric analysis of the thermal shear localization in EHL films. In Proceedings of the World Tribology Congress III - 2005 (pp. 543-544)
Chang, Liming. / A parametric analysis of the thermal shear localization in EHL films. Proceedings of the World Tribology Congress III - 2005. 2005. pp. 543-544
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abstract = "Experiments and computer simulations [1] have revealed some unusual results of elastohydrodynamic lubrication (EHL) associated with a high degree of thermally induced inhomogeneous shear across the lubricant film, or thermal shear localization. The results include the development of a sizable film dimple in the central EHL region [2] and a dramatic reduction in EHL traction [3, 4]. In this study, a theoretical analysis is carried out to determine the conditions under which the thermal shear localization may develop in EHL films. For a Newtonian lubricant obeying the Barus law of viscosity, a dimensionless group-parameter is identified that fully governs the degree of the thermal inhomogeneous shear. Results are presented that show the critical range of values of this parameter corresponding to the onset of the shear localization. The analysis is also extended to lubricants with non-Newtonian behavior. Results suggest that the same dimensionless group-parameter may be used to measure the degree of the shear localization when the lubricant viscosity in the parameter is replaced by an effective viscosity that accounts for the non-Newtonian effect. Reference [5] presents details of the theoretical formulation and results analysis.",
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Chang, L 2005, A parametric analysis of the thermal shear localization in EHL films. in Proceedings of the World Tribology Congress III - 2005. pp. 543-544, 2005 World Tribology Congress III, Washington, D.C., United States, 9/12/05.

A parametric analysis of the thermal shear localization in EHL films. / Chang, Liming.

Proceedings of the World Tribology Congress III - 2005. 2005. p. 543-544.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

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AB - Experiments and computer simulations [1] have revealed some unusual results of elastohydrodynamic lubrication (EHL) associated with a high degree of thermally induced inhomogeneous shear across the lubricant film, or thermal shear localization. The results include the development of a sizable film dimple in the central EHL region [2] and a dramatic reduction in EHL traction [3, 4]. In this study, a theoretical analysis is carried out to determine the conditions under which the thermal shear localization may develop in EHL films. For a Newtonian lubricant obeying the Barus law of viscosity, a dimensionless group-parameter is identified that fully governs the degree of the thermal inhomogeneous shear. Results are presented that show the critical range of values of this parameter corresponding to the onset of the shear localization. The analysis is also extended to lubricants with non-Newtonian behavior. Results suggest that the same dimensionless group-parameter may be used to measure the degree of the shear localization when the lubricant viscosity in the parameter is replaced by an effective viscosity that accounts for the non-Newtonian effect. Reference [5] presents details of the theoretical formulation and results analysis.

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Chang L. A parametric analysis of the thermal shear localization in EHL films. In Proceedings of the World Tribology Congress III - 2005. 2005. p. 543-544