This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
High-Accuracy Viscosity-Temperature Model for Engine Simulation
Technical Paper
2018-01-1805
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Language:
English
Abstract
In an era of accelerated engine efficiency development, the ability to accurately model lubricant performance is becoming increasingly important. The general behaviour of engine lubricant viscosity with temperature is well understood and for most applications the widely accepted models of Walther and Vogel are deemed accurate enough in their prediction of decreasing viscosity with increasing temperature. However, as we move further into a digitized age it becomes apparent there is a need for a single expression higher accuracy equation which captures this behaviour to better facilitate its use in automotive engineering simulation software (Computer Aided Engineering -CAE). Ideally it would be beneficial for a viscosity model to include standard viscosity parameters in a single expression that could be calibrated directly using standard viscosity measurements that are already in common use.
A key aspect which underpins models of lubricated surfaces is the ability to accurately predict viscosity. Any errors in a viscosity prediction for the lubricant which might otherwise seem minor at atmospheric pressure are exacerbated by the near exponential response of viscosity to contact pressure. This reinforces the requirement for a simple accurate solution.
In this paper a new single expression concept model has been explored refined and validated at both low and high shear rates and on both absolute and kinematic viscosity. Three key arrangements of the model are used as examples; a basic model (9), an enhanced model (10) and finally the enhanced model is examined over an extended temperature range (11). The benefits of each are explained, with the most advanced model accuracy investigated in greater depth and compared to measured data. The resultant error in the viscosity prediction is less than the quoted accuracy of the measuring equipment (0.2%) which then becomes the limiting accuracy factor for the model in this instance. Finally some examples of the model in use, embedded within CAE tools are discussed to demonstrate its applicability within more complex scenarios.
Recommended Content
Authors
Topic
Citation
Bucknall, J., "High-Accuracy Viscosity-Temperature Model for Engine Simulation," SAE Technical Paper 2018-01-1805, 2018, https://doi.org/10.4271/2018-01-1805.Also In
References
- Butcher , R.T. Spotting the Difference - Measuring Worthwhile Lubricant Related CO2 Benefits SAE 2016 World Congress and Exhibition 10.4271/2016-01-0890
- August , E.F. Ueber die Berechnung der Expansivkraft des Wasserdunstes Ann. Phys. Chem. 13 122 137 1828 10.1002/andp.18280890511
- Reynolds , O. On the Theory of Lubrication and Its Application to Mr Beauchamp Towers Experiments Including an Experimental Determination of the Viscosity of Olive Oil Philos. Trans. R. Soc. Lond. 177 157 234 1886 10.1098/rstl.1886.0005
- De Guzman , J. Anales de Ia Sociedad Espanola de Fisica y Quimica 119 3.53 1913
- Andrade , E.N.da.C. Nature 129 125 126 1932 DOI.org/10.1038/129125d0
- Antoine , C. Tensions des vapeurs; nouvelle relation entre les tensions et les températures Comptes Rendus des Séances de l’Académie des Sciences 107 681 684 1888
- Vogel , H. Physik Z. 22 645 1921
- Gutmann , F. and Simmons , L.M. Temperature Dependence of Viscosity of Liquids Journal of Applied Physics 23 977 1952 10.1063/1.1702361
- Eyring , H. Viscosity, Plasticity, and Diffusion as Examples of Absolute Reaction Rates The Journal of Chemical Physics 4 283 1936 10.1063/1.1749836
- Briant , J. , Denis , J. , and Parc , G. Propriétés rhéologiques des lubrifiants 1989 93
- MacCoull , N. Lubrication New York The Texas Company 1921 85
- Walther , C. ErdOl und Teer 4 510 1928
- Sánchez-Rubio , M. , Chinas-Castillo , F. , Ruiz-Aquino , F. , and Lara-Romero , J. A New Focus on the Walther Equation for Lubricant Viscosity Determination Lubrication Science 18 95 107 2006 10.1002/ls.9
- Seeton , C.J. Tribology Letters 2006 10.1007/s11249-006-9071-
- Bair , S. High Pressure Rheology for Quantitative Elastohydrodynamics 2007 9780444522436
- Hamrock , B.J. Fundamentals of Fluid Film Lubrication McGraw-Hill 1994 0-07-025956-9
- Ricardo Software
- PCS Ltd
- Greenwood , J.A. and Tripp , J.H. 10.1243/pime_proc_1970_185_069_02