Detail publikace

EHD simulace použitím modelu viskozity "free-volume"

LIU, Y. WANG, Q.J.WANG, W. HU, Y. ZHU, D. KŘUPKA, I. HARTL, M.

Český název

EHD simulace použitím modelu viskozity "free-volume"

Anglický název

EHL simulation using the free-volume viscosity model

Typ

článek v časopise - ostatní, Jost

Jazyk

en

Originální abstrakt

The free-volume viscosity model can accurately predict the temperature pressure viscosity relationship of lubricants. However, it is seldom used in elastohydrodynamic lubrication (EHL) simulation. This paper presents the application of the free-volume viscosity model in a Newtonian EHL simulation of a squalane-lubricated circular contact. Good agreement is observed between available experimental data and simulation results. The pressure viscosity coefficients fit from viscometer data are also discussed. A recently developed definition of the coefficient is used to compare the coefficient value extracted from EHL film thickness interference measurements. Results indicate that the coefficient values from the curve fitting and EHL film thickness extraction agree well which has not been previously observed. Two factors help achieve this agreement: the new coefficient definition and smaller prediction error when using the Hamrock Dowson formula in the cases studied. The effects of different pressure viscosity relationships, including the exponential model, the Roelands model and the free volume model, are investigated through an example with bright stock mineral oil. It is found that the real pressure viscosity behavior predicted by the free volume model yields a higher viscosity at the low pressure area which results in a larger central film thickness. Therefore, due to use of the free-volume model, the present results are more consistent with experimental observations than previously reported numerical results.

Český abstrakt

Prezentace nového numerického řešení problematiky EHD mazání založená na "free volume" modelu viskozity. Výsledky získané numerickou simulací srovnány s experimenty.

Anglický abstrakt

The free-volume viscosity model can accurately predict the temperature pressure viscosity relationship of lubricants. However, it is seldom used in elastohydrodynamic lubrication (EHL) simulation. This paper presents the application of the free-volume viscosity model in a Newtonian EHL simulation of a squalane-lubricated circular contact. Good agreement is observed between available experimental data and simulation results. The pressure viscosity coefficients fit from viscometer data are also discussed. A recently developed definition of the coefficient is used to compare the coefficient value extracted from EHL film thickness interference measurements. Results indicate that the coefficient values from the curve fitting and EHL film thickness extraction agree well which has not been previously observed. Two factors help achieve this agreement: the new coefficient definition and smaller prediction error when using the Hamrock Dowson formula in the cases studied. The effects of different pressure viscosity relationships, including the exponential model, the Roelands model and the free volume model, are investigated through an example with bright stock mineral oil. It is found that the real pressure viscosity behavior predicted by the free volume model yields a higher viscosity at the low pressure area which results in a larger central film thickness. Therefore, due to use of the free-volume model, the present results are more consistent with experimental observations than previously reported numerical results.

Klíčová slova anglicky

lubrication; film thickness

Rok RIV

2006

Vydáno

15.07.2006

Nakladatel

Springer Netherlands

Místo

Holandsko

ISSN

1023-8883

Časopis

Tribology Letters

Ročník

23

Číslo

1

Strany od–do

27–37

Počet stran

11

BIBTEX


@article{BUT43714,
  author="Ivan {Křupka} and Martin {Hartl},
  title="EHL simulation using the free-volume viscosity model",
  journal="Tribology Letters",
  year="2006",
  volume="23",
  number="1",
  month="July",
  pages="27--37",
  publisher="Springer Netherlands",
  address="Holandsko",
  issn="1023-8883"
}