Detail publikace
Experimentální ověření vlivu velikosti třecích těles v obecném Newtonovském EHD modelu
KŘUPKA, I. HARTL, M. BAIR, S. KUMAR, P. KHONSARI, M.M.
Český název
Experimentální ověření vlivu velikosti třecích těles v obecném Newtonovském EHD modelu
Anglický název
An Experimental Validation of the Recently Discovered Scale Effect in Generalized Newtonian EHL
Typ
článek v časopise - ostatní, Jost
Jazyk
en
Originální abstrakt
New quantitative numerical simulations of the elastohydrodynamic lubrication (EHL) film forming ability of generalized Newtonian liquids have elucidated a previously unrecognized property of EHL films. The dependency of the film thickness on the scale of the contact is greater when the viscosity is shear dependent within the inlet. Measurements of film thickness were performed in a ball on disc experiment using balls ranging from 5.5 to 35 mm in diameter. Three liquids were investigated with varying shear dependence in the range of stress important to film forming. The experimental results confirm the previous analytical findings. Numerical simulations using the measured viscosities show that the increased scale sensitivity is substantially the result of shear-thinning. However, the smallest scales produced films thinner than even the shear-dependent prediction, possibly indicating molecular degradation. It is quite likely that some machine components, which were designed using the effective viscous properties derived from a larger scale film thickness measurement, are operating with substantially lower film thickness than the designer had intended.
Český abstrakt
Článek shrnuje výsledky experimentálního ověření vlivu rozměrů třecích těles modelového kontaktu na přenositelnost získaných údajů na reálný mazaný kontakt.
Anglický abstrakt
New quantitative numerical simulations of the elastohydrodynamic lubrication (EHL) film forming ability of generalized Newtonian liquids have elucidated a previously unrecognized property of EHL films. The dependency of the film thickness on the scale of the contact is greater when the viscosity is shear dependent within the inlet. Measurements of film thickness were performed in a ball on disc experiment using balls ranging from 5.5 to 35 mm in diameter. Three liquids were investigated with varying shear dependence in the range of stress important to film forming. The experimental results confirm the previous analytical findings. Numerical simulations using the measured viscosities show that the increased scale sensitivity is substantially the result of shear-thinning. However, the smallest scales produced films thinner than even the shear-dependent prediction, possibly indicating molecular degradation. It is quite likely that some machine components, which were designed using the effective viscous properties derived from a larger scale film thickness measurement, are operating with substantially lower film thickness than the designer had intended.
Klíčová slova česky
Elastohydrodynamické mazání; Tloušťka filmu; Reologie
Klíčová slova anglicky
Elastohydrodynamic; Film thickness; EHL; Rheology
Rok RIV
2008
Vydáno
03.12.2008
Nakladatel
Springer
ISSN
1023-8883
Časopis
Tribology Letters
Ročník
33
Číslo
X
Strany od–do
1–9
Počet stran
9
BIBTEX
@article{BUT48047,
author="Ivan {Křupka} and Martin {Hartl},
title="An Experimental Validation of the Recently Discovered Scale Effect in Generalized Newtonian EHL",
journal="Tribology Letters",
year="2008",
volume="33",
number="X",
month="December",
pages="1--9",
publisher="Springer",
issn="1023-8883"
}