Abstract
iew Video Presentation: https://doi-org.tudelft.idm.oclc.org/10.2514/6.2021-2179.vid
The unsteady surface pressure fluctuations over trailing-edge serrations retrofitted to the benchmark NACA 633-018 profile are experimentally measured. Miniaturized unsteady pressure transducers installed on the serration surface are used to describe the temporal and spatial distribution of the wall pressure fluctuations over the trailing-edge add-on. The measured spectra, convection velocity, and correlation lengths of the surface pressure fluctuations are presented for the most upstream sensor and compared against the data at different locations along the serration surface. Different angles of attack are tested in a Reynolds number of 2,000,000 (based on the airfoil chord) in order to describe the properties of the wall pressure fluctuations at a range of representative conditions for wind turbine applications. The study details the characteristics of the wall-pressure fluctuations on the serration surface. In particular, the distribution of the wall-pressure fluctuations with and without aerodynamic loading caused by the variation of the airfoil angle of attack is shown, highlighting the impact of the vortex pairs formed around the edges of the serrations under loading on the wall-pressure fluctuations. The experimental results focus on the modifications of the wall-pressure fluctuations over the serration surface. Results show that, at small angles of attack, the amplitude of the wall-pressure fluctuations is higher at the serration root for low frequencies and at the serration tip for high frequencies. As the angle of attack increases, the aerodynamic loading over the serrations causes an increase in the wall pressure fluctuations around the edges of the serrations. This increase depends on the incoming fluctuations from the boundary layer and is related to the degradation of serration acoustic performance at angle. Furthermore, the experimental results corroborate to the benchmark activities for trailing-edge serration noise carried out in collaboration with DTU and DLR, providing information about the pressure fluctuations measured near the edges of the serration.
The unsteady surface pressure fluctuations over trailing-edge serrations retrofitted to the benchmark NACA 633-018 profile are experimentally measured. Miniaturized unsteady pressure transducers installed on the serration surface are used to describe the temporal and spatial distribution of the wall pressure fluctuations over the trailing-edge add-on. The measured spectra, convection velocity, and correlation lengths of the surface pressure fluctuations are presented for the most upstream sensor and compared against the data at different locations along the serration surface. Different angles of attack are tested in a Reynolds number of 2,000,000 (based on the airfoil chord) in order to describe the properties of the wall pressure fluctuations at a range of representative conditions for wind turbine applications. The study details the characteristics of the wall-pressure fluctuations on the serration surface. In particular, the distribution of the wall-pressure fluctuations with and without aerodynamic loading caused by the variation of the airfoil angle of attack is shown, highlighting the impact of the vortex pairs formed around the edges of the serrations under loading on the wall-pressure fluctuations. The experimental results focus on the modifications of the wall-pressure fluctuations over the serration surface. Results show that, at small angles of attack, the amplitude of the wall-pressure fluctuations is higher at the serration root for low frequencies and at the serration tip for high frequencies. As the angle of attack increases, the aerodynamic loading over the serrations causes an increase in the wall pressure fluctuations around the edges of the serrations. This increase depends on the incoming fluctuations from the boundary layer and is related to the degradation of serration acoustic performance at angle. Furthermore, the experimental results corroborate to the benchmark activities for trailing-edge serration noise carried out in collaboration with DTU and DLR, providing information about the pressure fluctuations measured near the edges of the serration.
| Original language | English |
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| Title of host publication | AIAA AVIATION 2021 FORUM |
| Number of pages | 15 |
| ISBN (Electronic) | 978-1-62410-610-1 |
| DOIs | |
| Publication status | Published - 2021 |
| Event | AIAA Aviation 2021 Forum - Virtual Event Duration: 2 Aug 2021 → 6 Aug 2021 |
Publication series
| Name | AIAA Aviation and Aeronautics Forum and Exposition, AIAA AVIATION Forum 2021 |
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Conference
| Conference | AIAA Aviation 2021 Forum |
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| Period | 2/08/21 → 6/08/21 |
Bibliographical note
Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-careOtherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.