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Experimental Investigation Into Oil Film Thickness and Behaviour Near an Aero-Engine Bearing

Sinha, Avick; Hann, David; Johnson, Kathy; Walsh, Michael

Authors

Avick Sinha

Michael Walsh



Abstract

In an aero-engine transmission system, bearings are used for shaft location and load support. These bearings are housed in bearing chambers and oil is supplied to the chamber for lubrication and cooling. To achieve the targets of ACARE Flight-path 2050, improved engine design, including the transmission oil system, is required, necessitating a better understanding of oil flow behaviour and management in the bearing chambers. The present work focuses on investigating oil flow behaviour on static surfaces near a bearing in a representative, purpose-built test rig, at four angular locations: 0°, 90°, 180° and 270° from top dead centre. The rig was run at shaft speeds up to a rotational Reynolds number of 1.7 × 106, for two oil flow rates and two axial load conditions. The investigation was conducted using high-speed imaging and subsequent detailed image analysis. These are the first experimental results obtained on this facility for film characteristics near the bearing slot at high shaft speeds. The current work has value both in terms of insights into the physics of the oil flow behaviour and also in generating high-quality data for comparison with CFD models. Three different film regimes were identified based on the shape of the film interface and these have been descriptively characterised as long wave, short wave and uniform film. Median film thickness obtained from image analysis was found to be highest at the 180° location and lowest at the 90° location. At all speed/load conditions investigated, the surface waves were found to be capillary waves.

Citation

Sinha, A., Hann, D., Johnson, K., & Walsh, M. (2022, June). Experimental Investigation Into Oil Film Thickness and Behaviour Near an Aero-Engine Bearing. Presented at ASME Turbo Expo 2022: Turbomachinery Technical Conference and Exposition, Rotterdam, Netherlands

Presentation Conference Type Edited Proceedings
Conference Name ASME Turbo Expo 2022: Turbomachinery Technical Conference and Exposition
Start Date Jun 13, 2022
End Date Jun 17, 2022
Acceptance Date Oct 22, 2022
Online Publication Date Oct 28, 2022
Publication Date Jun 13, 2022
Deposit Date Oct 9, 2024
Publisher American Society of Mechanical Engineers
Peer Reviewed Peer Reviewed
Volume 8-A
Book Title Proceedings of the ASME 2022 Turbomachinery Technical Conference & Exposition Turbo Expo 2022 June 13-17, 2022, Rotterdam, The Netherlands
ISBN 978-0-7918-8606-9
DOI https://doi.org/10.1115/GT2022-82180
Public URL https://nottingham-repository.worktribe.com/output/13449600
Publisher URL https://asmedigitalcollection.asme.org/GT/proceedings-abstract/GT2022/86069/V08AT22A009/1149105
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