Bair High Pressure Rheology for Quantitative Elastohydrodynamics

1. Auflage 2007
ISBN: 978-0-08-047530-1
Verlag: Elsevier Science & Techn.
Format: PDF
Kopierschutz: 1 - PDF Watermark

E-Book, Englisch, 260 Seiten, Web PDF

Computational elastohydrodynamics, a part of tribology, has existed happily enough for about fifty years without the use of accurate models for the rheology of the liquids used as lubricants. For low molecular weight liquids, such as low viscosity mineral oils, it has been possible to calculate, with precision, the film thickness in a concentrated contact provided that the pressure and temperature are relatively low, even when the pressure variation of viscosity is not accurately modelled in detail. Other successes have been more qualitative in nature, using effective properties which come from the fitting of parameters used in calculations to experimental measurements of the contact behaviour, friction or film thickness.
High Pressure Rheology for Quantitative Elastohydrodynamics is intended to provide a sufficiently accurate framework for the rheology of liquids at elevated pressure that it may be possible for computational elastohydrodynamics to discover the relationships between the behaviour of a lubricated concentrated contact and the measurable properties of the liquid lubricant. The required high-pressure measurement techniques are revealed in detail and data are presented for chemically well-defined liquids that may be used as quantitative reference materials.
* Presents the property relations required for a quantitative calculation of the tribological behaviour of lubricated concentrated contacts.
* Details of high-pressure experimental techniques.
* Complete description of the pressure and temperature dependence of viscosity for high pressures.
* Some little-known limitations on EHL modelling.

Autoren/Hrsg.

Bair, Scott S.

Inhaltsverzeichnis

1;Cover;1
2;Copyright page;5
3;Table of Contents;6
4;Preface;10
5;Nomenclature;12
6;Figure Credits;18
7;Acknowledgements;20
8;Chapter 1. An Introduction to Elastohydrodynamic Lubrication;22
8.1;1.1 Lubrication;22
8.2;1.2 Concentrated Contact Lubrication;23
8.3;1.3 Full Elastohydrodynamic Lubrication;28
8.4;1.4 Experimental Elastohydrodynamics;30
8.5;1.5 Conclusion;34
8.6;References;35
9;Chapter 2. An Introduction to the Rheology of Polymeric Liquids;36
9.1;2.1 Background;36
9.2;2.2 The Newtonian Model;37
9.3;2.3 Material Functions for Polymeric Liquids;39
9.4;2.4 Rheological Models;44
9.5;2.5 Time–Temperature–Pressure Superposition;51
9.6;2.6 Liquid Failure;53
9.7;References;53
10;Chapter 3. General High-Pressure Experimental Technique;56
10.1;3.1 Background;56
10.2;3.2 Pressure Containment;57
10.3;3.3 Closures;60
10.4;3.4 Feed-Throughs;63
10.5;3.5 Pressure Generation and Measurement;68
10.6;3.6 Hydrostatic Media and Volume Compensation;72
10.7;References;74
11;Chapter 4. Compressibility and the Equation of State;75
11.1;4.1 Background;75
11.2;4.2 PVT Measurement Techniques and Results;76
11.3;4.3 Empirical Equations of States;88
11.4;References;92
12;Chapter 5. The Pressure and Temperature Dependence of the Low-Shear Viscosity;94
12.1;5.1 Background;94
12.2;5.2 Viscometers for High Pressure;96
12.3;5.3 General Pressure–Viscosity Response and Results for Pure Organic Liquids and Lubricants;108
12.4;References;119
13;Chapter 6. Models for the Temperature and Pressure Dependence of Low-Shear Viscosity;122
13.1;6.1 Introduction;122
13.2;6.2 Models for the Temperature–Viscosity Response;123
13.3;6.3 Fragility and Empirical Models for High Pressure Behavior;125
13.4;6.4 The Pressure–Viscosity Coefficient and Empirical Models for Low Pressure Behavior;128
13.5;6.5 Empirical Models for Large Pressure Intervals;134
13.6;6.6 Models Based on Free Volume Theory;137
13.7;6.7 Generalized Temperature–Pressure–Viscosity Models;143
13.8;6.8 Multi-Component Systems;145
13.9;References;150
14;Chapter 7. Measurement Techniques for the Shear Dependence of Viscosity at Elevated Pressure;154
14.1;7.1 Introduction;154
14.2;7.2 Phenomena Producing Behavior Similar to Shear-Thinning;157
14.3;7.3 Rheometers for High Pressure;163
14.4;References;178
15;Chapter 8. The Shear Dependence of Viscosity at Elevated Pressure;181
15.1;8.1 Introduction;181
15.2;8.2 Normal Stress Differences at Elevated Pressures;184
15.3;8.3 The Origin of Non-Newtonian Behavior in Low-Molecular-Weight Liquids at Elevated Pressures;187
15.4;8.4 Time–Temperature–Pressure Superposition;192
15.5;8.5 The Competition between Thermal Softening and Shear-Thinning;195
15.6;8.6 Multi-Component Systems;196
15.7;8.7 The Power-Law Exponent and the Second Newtonian Viscosity;198
15.8;References;200
16;Chapter 9. The Glass Transition and Related Transitions in Liquids Under Pressure;204
16.1;9.1 Measurements of Glass Transition at Elevated Pressure;204
16.2;9.2 Measurements of Dielectric Transition at Elevated Pressure;207
16.3;9.3 The Transitions as Isoviscous States;209
16.4;9.4 The Pressure Variation of Viscosity across the Transition;211
16.5;References;212
17;Chapter 10. Shear Localization, Slip and the Limiting Stress;214
17.1;10.1 Introduction;214
17.2;10.2 Measurements of Rate Independent Shear Stress;216
17.3;10.3 Flow Visualization of Shear Bands;218
17.4;10.4 Mohr–Coulomb Failure Criterion;221
17.5;10.5 Change of Character of the Piezoviscous Navier–Stokes Equations;223
17.6;10.6 Thermal Localization, Adiabatic Shear Bands;224
17.7;10.7 Interfacial Slip;225
17.8;References;225
18;Chapter 11. The Reynolds Equation;227
18.1;11.1 Background;227
18.2;11.2 Reynolds Equations for Generalized Newtonian Fluids;230
18.3;References;237
19;Chapter 12. Applications to Elastohydrodynamics;239
19.1;12.1 Introduction;239
19.2;12.2 Film Thickness for Shear-Thinning Liquids;241
19.3;12.3 The Calculation of Traction from Material Properties;248
19.4;References;257
20;Index;259