Classical EHL Versus Quantitative EHL: A Perspective Part I—Real Viscosity-Pressure Dependence and the Viscosity-Pressure Coefficient for Predicting Film Thickness

That classical elastohydrodynamic lubrication (EHL) is not a quantitative field can be illustrated by its failure to provide a consistent and rigorous definition of the viscosity-pressure coefficient. Indeed, if the pressure dependence of viscosity cannot be accurately described, then the viscosity-pressure coefficient cannot be defined. Classical EHL has employed fictional narratives to justify the pressure dependences that have been utilized. In this context, the purpose of this perspective article is to review specific and real needs from EHL and to show that data and models describing the viscosity-pressure dependence are already available and how they can properly be used. The final aim is to encourage researchers to change their philosophy of classical EHL to a quantitative approach, in which every hypothesis and every result, whether experimental or numerical, would be justified on the basis of acceptable physics.

[1]  Percy Williams Bridgman,et al.  The Effect of Pressure on the Viscosity of Forty-Three Pure Liquids , 1926 .

[2]  D. Dowson.  History of Tribology , 1979 .

[3]  S. Bair,et al.  Influence of pressure and temperature dependence of thermal properties of a lubricant on the behaviour of circular TEHD contacts , 2010 .

[4]  M. Huggins.  Viscoelastic Properties of Polymers. , 1961 .

[5]  Scott Bair,et al.  High Pressure Rheology for Quantitative Elastohydrodynamics , 2007 .

[6]  Ward O. Winer,et al.  An Application of a Free Volume Model to Lubricant Rheology I—Dependence of Viscosity on Temperature and Pressure , 1984 .

[7]  B. Wolf,et al.  Temperature and pressure dependence of the viscosities of perfluoropolyether fluids , 1987 .

[8]  Scott Bair,et al.  Reference liquids for quantitative elastohydrodynamics: selection and rheological characterization , 2006 .

[9]  S. Bair.  The temperature and pressure dependence of the dynamic properties of branched perfluoropolyethers , 2014 .

[10]  S. Bair,et al.  Thermal Elastohydrodynamic Lubrication of Point Contacts Using a Newtonian/Generalized Newtonian Lubricant , 2008 .

[11]  Philippe Vergne,et al.  On friction regimes in quantitative elastohydrodynamics , 2013 .

[12]  C. Venner,et al.  Effects of lubricant compressibility on the film thickness in EHL line and circular contacts , 1994 .

[13]  William R. Jones,et al.  Properties of Perfluoropolyethers for Space Applications , 1995 .

[14]  Philippe Vergne,et al.  A unified shear-thinning treatment of both film thickness and traction in EHD , 2005, 0704.1798.

[15]  A Dual Experimental/Numerical Approach for Film Thickness Analysis in TEHL Spinning Skewing Circular Contacts , 2013, Tribology Letters.

[16]  S. Bair,et al.  A Quantitative Solution for the Full Shear-Thinning EHL Point Contact Problem Including Traction , 2007 .

[17]  Richard L. Cook,et al.  Pressure and temperature dependent viscosity of two glass forming liquids: Glycerol and dibutyl phthalate , 1994 .

[18]  Philippe Vergne,et al.  The Effect of Shear-Thinning on Film Thickness for Space Lubricants , 2002 .

[19]  P. Vergne,et al.  High pressure rheology for high pressure lubrication: A review , 1990 .

[20]  G. Dalmaz,et al.  Experimental results and analytical film thickness predictions in EHD rolling point contacts , 2007 .

[21]  D. Dowson,et al.  Isothermal Elastohydrodynamic Lubrication of Point Contacts: Part 1—Theoretical Formulation , 1975 .

[22]  Ward O. Winer,et al.  The temperature, pressure and time dependence of lubricant viscosity , 2001 .

[23]  R. Scott.  Molecular theory of gases and liquids , 1955 .

[24]  S. Bair,et al.  A Rheological Model for Elastohydrodynamic Contacts Based on Primary Laboratory Data , 1979 .

[25]  S. Bair.  An Experimental Verification of the Significance of the Reciprocal Asymptotic Isoviscous Pressure for EHD Lubricants. , 1993 .

[26]  Jérôme Molimard,et al.  Thin Film Colorimetric Interferometry , 2001 .

[27]  Hisung Lee,et al.  A numerical solution to the elastohydrodynamic problem incorporating a non-newtonian rheological model , 1991 .

[28]  F. Murnaghan.  The Compressibility of Media under Extreme Pressures. , 1944, Proceedings of the National Academy of Sciences of the United States of America.

[29]  P. Vergne,et al.  Viscoelastic Parameters of 5P4E as a Function of Pressure and Temperature by Light Scattering Technique , 1986 .

[30]  D. Dowson,et al.  A Numerical Solution to the Elasto-Hydrodynamic Problem , 1959 .

[31]  S. Bair,et al.  New Insight into the Relationship Between Molecular Effects and the Rheological Behavior of Polymer-Thickened Lubricants Under High Pressure , 2013, Tribology Letters.

[32]  M. Kamel,et al.  Behavior of Cold-Rolling Oil-in-Water Emulsions: A Rheological Approach , 1997 .

[33]  Bill Wilson,et al.  History of Tribology (2nd ed.) , 1998 .

[34]  S. Bair,et al.  An improved Yasutomi correlation for viscosity at high pressure , 2013 .

[35]  P. Vergne,et al.  Numerical insight into heat transfer and power losses in spinning EHD non-Newtonian point contacts , 2012 .

[36]  C. F. Curtiss,et al.  Molecular Theory Of Gases And Liquids , 1954 .

[37]  H. Blok,et al.  Inverse problem in hydrodynamic lubrication and design directives for lubricated flexible surfaces , 1963 .

[38]  D. Mazuyer,et al.  Correlation between the Film Forming Ability and Rheological Properties of New and Aged Low Sulfated Ash, Phosphorus and Sulfur (Low SAPS) Automotive Lubricants , 2009 .

[39]  S. Bair,et al.  The Pressure-Viscosity Coefficient for Newtonian EHL Film Thickness With General Piezoviscous Response , 2006 .

[40]  S. Bair,et al.  A Scaling Parameter and Function for the Accurate Correlation of Viscosity With Temperature and Pressure Across Eight Orders of Magnitude of Viscosity , 2008 .

[41]  Daniel Nelias,et al.  Traction Behavior of Some Lubricants Used for Rolling Bearings in Spacecraft Applications: Experiments and Thermal Model Based on Primary Laboratory Data , 2002 .

[42]  이재복.  의사 간호사 communication , 2011 .

[43]  Arthur K. Doolittle,et al.  Studies in Newtonian Flow. II. The Dependence of the Viscosity of Liquids on Free‐Space , 1951 .

[44]  D. Dowson,et al.  Isothermal Elastohydrodynamic Lubrication of Point Contacts: Part III—Fully Flooded Results , 1976 .