3D Measurements of Lubricant and Surface Temperatures Within an Elastohydrodynamic Contact
File(s)10.1007%2Fs11249-017-0953-2.pdf (2.37 MB)
Published version
Author(s)
Lu, J
Reddyhoff, T
Dini, D
Type
Journal Article
Abstract
We present an infrared microscopy technique, capable of measuring the temperature of both the bounding surfaces and the oil film in an elastohydrodynamic contact. This technique can, for the first time, spatially resolve the oil film temperature in three dimensions. The contact is produced by loading a steel ball against a sapphire disc, and the film is viewed using an infrared microscope focussing through the disc. Two band pass filters are used to isolate the radiation from the oil film, and Planck’s law is applied to data obtained at a known temperature as part of the calibration procedure. The proposed technique requires the emissivity of the oil film to be measured, which is acquired in situ and is shown to vary strongly as a function of thickness and temperature. The technique is validated under pure rolling conditions, when the temperature of the oil film is equal to the controlled lubricant reservoir temperature, and also compared to an equation commonly used to predict average film temperatures, confirming the value of the unknown constant. The technique is then used to gain insights into the thermal/rheological behaviour within a contact. This is important since the temperature of elastohydrodynamic contacts is critical in determining friction and hence the efficiency of machine components and this technique enables much needed validation and provides input data for CFD and numerical simulations.
Date Issued
2017-11-27
Date Acceptance
2017-11-27
Citation
Tribology Letters, 2017, 66
ISSN
1023-8883
Publisher
Springer Verlag
Journal / Book Title
Tribology Letters
Volume
66
Copyright Statement
© The Author(s) 2017. This article is an open access publication
License URL
Sponsor
Engineering & Physical Science Research Council (EPSRC)
Grant Number
EP/N025954/1
Subjects
0912 Materials Engineering
0913 Mechanical Engineering
Mechanical Engineering & Transports
Publication Status
Published
Article Number
7