Arun Prabhakar
Effect of vortex shedding on the performance of scoop based lubrication devices
Prabhakar, Arun; Abakr, Yousif Abdalla; Simmons, Kathy
Authors
Yousif Abdalla Abakr
KATHY JOHNSON KATHY.JOHNSON@NOTTINGHAM.AC.UK
Professor of Mechanical and Aerospace Engineering
Contributors
A. Prabhakar
Other
Y.A. Abakr
Other
KATHY JOHNSON KATHY.JOHNSON@NOTTINGHAM.AC.UK
Other
Abstract
In civil aircraft aeroengine bearing chambers it is sometimes difficult to feed oil to bearings using the traditional under-race or targeted jet approaches. In such situations one proposed solution is that of a scoop delivery system. Published experimental investigations into scoop performance show that scoop collection efficiency (the percentage of oil delivered by the scoop system to its destination compared to that supplied by the feed jet) is a function of many operational and geometric parameters. However even with high speed imaging it is impossible to experimentally determine in detail the factors that most contribute to reduction in collection efficiency and it is here particularly that a computational fluid dynamics (CFD) investigation has value. In the work reported here a commercial CFD code (ANSYS Fluent) is used to investigate vortex formation at the scoop tips and the effect these structures have on scoop collection efficiency. The computational domain, a 2D slice through the chosen scoop system, is discretized utilizing ANSYS Meshing. A Volume of fluid (VOF) method is used to model the multiphase flow of oil and air in the system and the RNG k-ϵ turbulence model is employed. The results obtained show that the formation of vortices from the tip of the rotating scoops leads to a reduction in pressure in the region near the tip of the oil jet, subsequently causing part of the jet to divert upwards away from the scoop creating a plumed tip. The pluming effect reduces capture efficiency because the oil plume moves outwards under centrifugal effects and this oil is not captured. The frequency of vortex shedding from the scooped rotor was investigated and the Strouhal numbers obtained were around 0.132. This compares well to 0.15 for an inclined flat plate. Two potential methods to reduce the jet pluming effect are investigated one in which the sharp tip of the scoop is blunted and the other in which the jet direction is reversed. The blunt tip increased capture efficiency by almost 2%. Reversing the jet orientation reduces jet pluming but also significantly reduces capture efficiency; it was found to be 10% lower for the case investigated.
Conference Name | ASME Turbo Expo 2017: Turbomachinery Technical Conference and Exposition |
---|---|
Conference Location | Charlotte, North Carolina, USA |
Start Date | Jun 26, 2017 |
End Date | Jun 30, 2017 |
Online Publication Date | Aug 17, 2017 |
Publication Date | Jun 30, 2017 |
Deposit Date | Jul 31, 2023 |
Volume | Volume 7A: Structures and Dynamics |
Series Title | ASME Turbo Expo : Turbomachinery Technical Conference and Exposition |
Book Title | Proceedings of Turbo Expo 2017: Turbomachinery Technical Conference and Exposition |
ISBN | 9780791850923 |
DOI | https://doi.org/10.1115/GT2017-63444 |
Public URL | https://nottingham-repository.worktribe.com/output/23541489 |
Publisher URL | https://asmedigitalcollection.asme.org/GT/proceedings-abstract/GT2017/50923/V07AT34A008/242714 |
You might also like
GT2022-82180 Experimental investigation into oil film thickness and behaviour near an aero-engine bearing
(2022)
Conference Proceeding
Experimental Investigation Into Oil Shedding From a Rotating Cup Geometry
(2022)
Conference Proceeding
Numerical Investigation Into Maximum Pressure Capability of Intershaft Hydraulic Seals
(2022)
Conference Proceeding
Investigation of Droplet Shedding in an Aeroengine Bearing Chamber Using Convolutional Neural Networks
(2022)
Conference Proceeding
Downloadable Citations
About Repository@Nottingham
Administrator e-mail: discovery-access-systems@nottingham.ac.uk
This application uses the following open-source libraries:
SheetJS Community Edition
Apache License Version 2.0 (http://www.apache.org/licenses/)
PDF.js
Apache License Version 2.0 (http://www.apache.org/licenses/)
Font Awesome
SIL OFL 1.1 (http://scripts.sil.org/OFL)
MIT License (http://opensource.org/licenses/mit-license.html)
CC BY 3.0 ( http://creativecommons.org/licenses/by/3.0/)
Powered by Worktribe © 2024
Advanced Search