Publication result detail

Quantitative elastohydrodynamic film thickness of mechanically degraded oil

BAIR, S.; ŠPERKA, P.; KŘUPKA, I.; HARTL, M.

Original Title

Quantitative elastohydrodynamic film thickness of mechanically degraded oil

English Title

Quantitative elastohydrodynamic film thickness of mechanically degraded oil

Type

Peer-reviewed article not indexed in WoS or Scopus

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.

English 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

Viscosity modifier; High pressure rheology; EHL film thickness; Mechanical shear degradation

Key words in English

Viscosity modifier; High pressure rheology; EHL film thickness; Mechanical shear degradation

Authors

BAIR, S.; ŠPERKA, P.; KŘUPKA, I.; HARTL, M.

RIV year

2014

Released

19.02.2013

Publisher

Elsevier

Location

EU

ISBN

0301-679X

Periodical

Tribology International

Volume

65

Number

8

State

United Kingdom of Great Britain and Northern Ireland

Pages from

33

Pages to

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"
}