Publication detail
Quantitative elastohydrodynamic film thickness of mechanically degraded oil
BAIR, S. ŠPERKA, P. KŘUPKA, I. HARTL, M.
English title
Quantitative elastohydrodynamic film thickness of mechanically degraded oil
Type
Peer-reviewed article not indexed in WoS or Scopus
Language
en
Original abstract
The low-shear viscosities of new oil and used (degraded) oil were measured to moderately high pressure. Shear-thinning flow curves were generated over a range of shear stress important to EHL film forming. Mechanical shear degradation only affected the viscosity at low shear stress while the viscosity at high stress remained unchanged. A recently published film thickness equation for double-Newtonian shear-thinning, employing the measured rheology, predicts the surprising result that thickness of the EHL film was not changed by the degradation although the low-shear viscosities were reduced substantially. Colorimetric measurements of the film thicknesses validate the predictions. Concern over the permanent loss in viscosity due to degradation may be misplaced when addressing EHL films.
Keywords in English
Viscosity modifier; High pressure rheology; EHL film thickness; Mechanical shear degradation
Released
2013-02-19
Publisher
Elsevier
Location
EU
ISSN
0301-679X
Journal
Tribology International
Volume
65
Number
8
Pages from–to
33–38
Pages count
6
BIBTEX
@article{BUT103166,
author="BAIR, S. and ŠPERKA, P. and KŘUPKA, I. and HARTL, M.",
title="Quantitative elastohydrodynamic film thickness of mechanically degraded oil",
journal="Tribology International",
year="2013",
volume="65",
number="8",
pages="33--38",
issn="0301-679X"
}