Abstract
Coating a circular cylinder with porous materials constitutes an effective passive strategy for reducing the flow-induced noise linked to the vortex shedding. Despite the number of investigations in the last decade, the noise-mitigation mechanisms associated with this technique remain unclear. The present research aims to clarify the role played by the alterations in the flow field due to porosity in the aerodynamic-sound attenuation of a cylinder coated with metal foam. Far-field acoustic and particle-image-velocimetry (PIV) measurements were performed at the Delft University of Technology for Reynolds numbers ranging in the subcritical regime. The aeroacoustic results show that a significant tonal and broadband suppression could be achieved with the porous treatment of the body. For the coated cylinder, the dominant sources do not appear to be distributed over the surface but rather are situated several diameters downstream of it, with a lower amplitude. The PIV data reveal that the main effect of the coating is to stabilize the cylinder wake, which results in an elongation of the vortex-formation length and a decrease in the turbulence kinetic energy. In particular, the position where the vortex shedding starts corresponds to the region of the dominant noise sources. The conclusions drawn in this study potentially provide an insightful indication for the design of more effective sound-control solutions.
Original language | English |
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Title of host publication | 28th AIAA/CEAS Aeroacoustics 2022 Conference |
Number of pages | 14 |
ISBN (Electronic) | 978-1-62410-664-4 |
DOIs | |
Publication status | Published - 2022 |
Event | 28th AIAA/CEAS Aeroacoustics 2022 Conference - Southampton, United Kingdom Duration: 14 Jun 2022 → 17 Jun 2022 Conference number: 28 |
Publication series
Name | 28th AIAA/CEAS Aeroacoustics Conference, 2022 |
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Conference
Conference | 28th AIAA/CEAS Aeroacoustics 2022 Conference |
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Country/Territory | United Kingdom |
City | Southampton |
Period | 14/06/22 → 17/06/22 |