Publication detail

Is Elastohydrodynamic Minimum Film Thickness Truly Governed by Inlet Rheology?

HABCHI, W. ŠPERKA, P. BAIR, S.

English title

Is Elastohydrodynamic Minimum Film Thickness Truly Governed by Inlet Rheology?

Type

journal article in Web of Science

Language

en

Original abstract

This work investigates the governing mechanisms of minimum film thickness in elastohydrodynamic lubricated contacts. Up until now, it was thought to be governed by lubricant rheology in the low-pressure contact inlet. Through numerical simulations of EHL line and circular contacts, lubricated with fluids having the same low-pressure viscosity, but a very different response at high-pressure, minimum film thickness is shown to be governed by lubricant inlet rheology only in the theoretical line contact configuration. In real contacts however, it is not only governed by inlet rheology, but also by the high-pressure viscosity response of the lubricant. It is observed that the greater the viscosity at high pressure, the lower the minimum film thickness would be, as a result of reduced lateral flow out of the contact. Conservation of mass requires then that a higher minimum film thickness would be attained along the central line of the contact, in the entrainment direction. These findings corroborate well with experimental observations.

English abstract

This work investigates the governing mechanisms of minimum film thickness in elastohydrodynamic lubricated contacts. Up until now, it was thought to be governed by lubricant rheology in the low-pressure contact inlet. Through numerical simulations of EHL line and circular contacts, lubricated with fluids having the same low-pressure viscosity, but a very different response at high-pressure, minimum film thickness is shown to be governed by lubricant inlet rheology only in the theoretical line contact configuration. In real contacts however, it is not only governed by inlet rheology, but also by the high-pressure viscosity response of the lubricant. It is observed that the greater the viscosity at high pressure, the lower the minimum film thickness would be, as a result of reduced lateral flow out of the contact. Conservation of mass requires then that a higher minimum film thickness would be attained along the central line of the contact, in the entrainment direction. These findings corroborate well with experimental observations.

Keywords in English

Elastohydrodynamic lubrication; Minimum film thickness; High-pressure rheology

Released

30.09.2023

Publisher

Springer Nature

Location

NEW YORK

ISSN

1023-8883

Volume

71

Number

3

Pages count

9

BIBTEX


@article{BUT187551,
  author="Wassim {Habchi} and Petr {Šperka} and Scott {Bair},
  title="Is Elastohydrodynamic Minimum Film Thickness Truly Governed by Inlet Rheology?",
  year="2023",
  volume="71",
  number="3",
  month="September",
  publisher="Springer Nature",
  address="NEW YORK",
  issn="1023-8883"
}