Effect of serrated trailing edges on aerofoil tonal noise
Effect of serrated trailing edges on aerofoil tonal noise
A wall-resolved large-eddy simulation of a symmetric Joukowski aerofoil with a 12 % thickness at a Reynolds number of 250 000, a Mach number of 0.4 and zero incidence angle is performed in order to investigate the effect of using a serrated trailing edge on the acoustic feedback event that generates a tonal noise. The acoustic feedback is investigated in detail to emphasise the interaction between the upstream travelling acoustic expansion wave and the laminar separation bubble. The simulation shows that the serrated trailing edges may result in a significant reduction of the tonal noise. This paper provides detailed investigations into the noise reduction mechanisms. The main finding is that the presence of a serrated trailing edge decreases the amplitude of the acoustic source pressure in the transitional region and gives rise to destructive phase interference in the wall pressure fluctuations in the vicinity of the trailing edge which weakens the acoustic feedback loop.
Aeroacoustics, Flow-structure interactions, Turbulence simulation
Gelot, Matthieu Bernard Roger
e5285772-2f53-47f2-90d0-49193d9c5cae
Kim, Jae
fedabfc6-312c-40fd-b0c1-7b4a3ca80987
10 December 2020
Gelot, Matthieu Bernard Roger
e5285772-2f53-47f2-90d0-49193d9c5cae
Kim, Jae
fedabfc6-312c-40fd-b0c1-7b4a3ca80987
Gelot, Matthieu Bernard Roger and Kim, Jae
(2020)
Effect of serrated trailing edges on aerofoil tonal noise.
Journal of Fluid Mechanics, 904, [A30].
(doi:10.1017/jfm.2020.724).
Abstract
A wall-resolved large-eddy simulation of a symmetric Joukowski aerofoil with a 12 % thickness at a Reynolds number of 250 000, a Mach number of 0.4 and zero incidence angle is performed in order to investigate the effect of using a serrated trailing edge on the acoustic feedback event that generates a tonal noise. The acoustic feedback is investigated in detail to emphasise the interaction between the upstream travelling acoustic expansion wave and the laminar separation bubble. The simulation shows that the serrated trailing edges may result in a significant reduction of the tonal noise. This paper provides detailed investigations into the noise reduction mechanisms. The main finding is that the presence of a serrated trailing edge decreases the amplitude of the acoustic source pressure in the transitional region and gives rise to destructive phase interference in the wall pressure fluctuations in the vicinity of the trailing edge which weakens the acoustic feedback loop.
Text
ste_tonal_noise_reduction
- Author's Original
Text
JFM-20-S-0615.R2_Proof_hi
- Accepted Manuscript
More information
Accepted/In Press date: 23 August 2020
e-pub ahead of print date: 13 October 2020
Published date: 10 December 2020
Additional Information:
Funding Information:
We would like to acknowledge the support of VESTAS for this work, with special thanks to Dr R. Serré, Mr D. Samora Cerqueira and Mr T. Vronsky. We also would like to thank EPSRC for the computational time made available on the UK supercomputing facility ARCHER via the UK Turbulence Consortium (EP/R029326/1), and the local IRIDIS-4 at the University of Southampton. All data supporting this study are openly available from the University of Southampton repository at doi:10.5258/SOTON/D1520 .
Publisher Copyright:
© The Author(s), 2020. Published by Cambridge University Press
Keywords:
Aeroacoustics, Flow-structure interactions, Turbulence simulation
Identifiers
Local EPrints ID: 443649
URI: http://eprints.soton.ac.uk/id/eprint/443649
ISSN: 0022-1120
PURE UUID: 8b0214c9-25d7-4849-9d06-e483655db788
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Date deposited: 07 Sep 2020 16:30
Last modified: 17 Mar 2024 05:51
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Author:
Matthieu Bernard Roger Gelot
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