TURBO-19-1210-The Influence of Fan Root Flow on the Aerodynamic of a Low-Pressure Compressor Transition Duct.pdf (5.38 MB)
The influence of fan root flow on the aerodynamic of a low-pressure compressor transition duct
journal contribution
posted on 2019-10-28, 11:15 authored by Duncan WalkerDuncan Walker, Ian MariahIan Mariah, Dimitra Tsakmakidou, Hiren Vadhvana, Chris HallTo reduce fuel-burn and emissions there is a drive towards higher bypass ratio and smaller high-pressure ratio core engines. This makes the design of the ducts connecting compressor spools more challenging as the higher radius change increases aerodynamic loading. This is exacerbated at inlet to the engine core by fan root flow which is characterised by a hub-low pressure profile and large secondary flow structures. Additionally, shorter, lighter nacelles mean that the intake may not provide a uniform inlet flow when the aircraft is at an angle of attack or subject to cross winds. Such inlet distortion can further degrade the flow entering the engine. A combination of experiments and CFD have been used to examine the aerodynamics of an engine section splitter (ESS) and transition duct designed to feed the low-pressure spool of a high bypass ratio turbofan. A test facility incorporating a 1½ stage axial compressor was used to compare system performance for a flat rotor exit profile to one with a hub deficient flow. Validated RANS CFD was then used to further investigate the effects of increased inlet boundary layer thickness and bulk swirl distortion at rotor inlet. These changes were seen to have a surprisingly small effect on the flow at duct exit. However, increased secondary flows were observed which degraded the performance of the ESS and significantly increased loss. Nevertheless, the enhanced mixing delayed separation in the duct suggesting that overall the design was reasonably robust albeit with increased system loss.
Funding
Aerospace Technology Institute as part of the iCORE (Integrated Core Technologies) program.
History
School
- Aeronautical, Automotive, Chemical and Materials Engineering
Department
- Aeronautical and Automotive Engineering
Published in
Journal of TurbomachineryVolume
142Issue
1Publisher
American Society of Mechanical EngineersVersion
- AM (Accepted Manuscript)
Rights holder
© ASMEPublisher statement
This is an Open Access Article. It is published by ASME under the Creative Commons Attribution 4.0 Unported Licence (CC BY). Full details of this licence are available at: http://creativecommons.org/licenses/by/4.0/Acceptance date
2019-10-18Publication date
2019-10-22Copyright date
2020ISSN
0889-504XeISSN
1528-8900Publisher version
Other identifier
Paper No: TURBO-19-1210Language
- en