Samenvatting
The Ultrathin Film Measurement System as a Rheometer
(using the Moes film thickness formula)
The objective of this study is an inexpensive general purpose method to determine the pressure viscosity alpha of a lubricant at high pressure, by combining the accuracy of the PCS Instruments Ultrathin Film Thickness Measurement system with the most accurate and general film thickness formula for EHD lubrication ever.
Values of alpha can be determined using a good approximation for the central film thickness in EHD lubricated contact.
When comparing the most cited by far expression from Hamrock and Dowson (1977) and Hamrock et al. (2004) for the central film thickness in elliptical EHD contacts with the more complex Moes (2000) approximation, the differences are obvious. Moes’ formulas are based on a much broader set of data for operational conditions as well as for odd geometries (very short as well as very wide ellipses).
It is found that the PCS system works in an enormous range of EHD conditions (esp. speeds and temperatures). The Moes formula for elliptical EHD lubricated contact can be very much recommended and is superior to the recent Hamrock et al. (2004) approximation. The film thickness results can be fitted by the best approximation formula, inclusive the best choice of possible alpha values. This allows the PCS system to be used as a versatile alternative to determine the pressure viscosity coefficient.
(using the Moes film thickness formula)
The objective of this study is an inexpensive general purpose method to determine the pressure viscosity alpha of a lubricant at high pressure, by combining the accuracy of the PCS Instruments Ultrathin Film Thickness Measurement system with the most accurate and general film thickness formula for EHD lubrication ever.
Values of alpha can be determined using a good approximation for the central film thickness in EHD lubricated contact.
When comparing the most cited by far expression from Hamrock and Dowson (1977) and Hamrock et al. (2004) for the central film thickness in elliptical EHD contacts with the more complex Moes (2000) approximation, the differences are obvious. Moes’ formulas are based on a much broader set of data for operational conditions as well as for odd geometries (very short as well as very wide ellipses).
It is found that the PCS system works in an enormous range of EHD conditions (esp. speeds and temperatures). The Moes formula for elliptical EHD lubricated contact can be very much recommended and is superior to the recent Hamrock et al. (2004) approximation. The film thickness results can be fitted by the best approximation formula, inclusive the best choice of possible alpha values. This allows the PCS system to be used as a versatile alternative to determine the pressure viscosity coefficient.
| Vertaalde titel van de bijdrage | Het ultra dunne filmdikte meetsysteem als reometer: gebruikmakend van de Moes filmdikteformule |
|---|---|
| Originele taal-2 | Engels |
| Titel | 3. Arnold Tross Kolloquium, 8 June 2007, Hamburg, Germany |
| Redacteuren | Erik Kuhn |
| Plaats van productie | Aachen |
| Uitgeverij | Shaker-Verlag |
| Pagina's | 131-165 |
| Aantal pagina's | 35 |
| ISBN van geprinte versie | 978-3-8322-6896-1 |
| Status | Gepubliceerd - 2008 |
| Evenement | 3rd Arnold Tross Kolloquium - Hamburg, Duitsland Duur: 8 jun. 2007 → 8 jun. 2007 |
Congres
| Congres | 3rd Arnold Tross Kolloquium |
|---|---|
| Land/Regio | Duitsland |
| Stad | Hamburg |
| Periode | 8/06/07 → 8/06/07 |