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Shahmohamadi, et al 2015 (Trib Letts,v57,n2,pp).pdf (2.27 MB)

Big end bearing losses with thermal cavitation flow under cylinder deactivation

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journal contribution
posted on 2015-03-27, 15:03 authored by Hamed Shahmohamadi, Ramin RahmaniRamin Rahmani, Homer Rahnejat, Colin GarnerColin Garner, D. Dowson
The paper presents a mixed thermo-hydrodynamic analysis of elliptic bore bearings using combined solution of Navier–Stokes, continuity and energy equations for multi-phase flow conditions. A vapour transport equation is also included to ensure continuity of flow in the cavitation region for the multiple phases as well as Rayleigh–Plesset to take into account the growth and collapse of cavitation bubbles. This approach removes the need to impose artificial outlet boundary conditions in the form of various cavitation algorithms which are often employed to deal with lubricant film rupture and reformation. The predictions show closer conformance to experimental measurements than have hitherto been reported in the literature. The validated model is then used for the prediction of frictional power losses in big end bearings of modern engines under realistic urban driving conditions. In particular, the effect of cylinder deactivation (CDA) upon engine bearing efficiency is studied. It is shown that big-end bearings losses contribute to an increase in the brake specific fuel consumption with application of CDA contrary to the gains made in fuel pumping losses to the cylinders. The study concludes that implications arising from application of new technologies such as CDA should also include their effect on tribological performance.

Funding

The authors would like to express their gratitude to the Lloyd’s Register Foundation (LRF) for the financial support extended to this research.

History

School

  • Mechanical, Electrical and Manufacturing Engineering

Published in

Tribology Letters

Volume

57

Issue

2

Citation

SHAHMOHAMADI, H. ... et al., 2015. Big end bearing losses with thermal cavitation flow under cylinder deactivation. Tribology Letters, 57 (2), 17pp. DOI: 10.1007/s11249-014-0444-7

Publisher

© The Author(s). This article is published with open access at Springerlink.com

Version

  • VoR (Version of Record)

Publisher statement

This work is made available according to the conditions of the Creative Commons Attribution 4.0 International (CC BY 4.0) licence. Full details of this licence are available at: http://creativecommons.org/licenses/ by/4.0/

Publication date

2015

Notes

This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited.

ISSN

1023-8883

Language

  • en