Abstract
This study investigates the flow topology and noise emission from an airfoil with combed teeth trailing edge geometry, to understand the noise reduction mechanisms observed in earlier experiments. A comparison is made to a straight trailing edge and a serrated trailing edge without combs. The different trailing edges are retrofitted to a NACA0018 airfoil at zero angle of attack. The flow field is analyzed by evaluating the fully explicit, transient, compressible Lattice Boltzmann equation. The acoustic far field is obtained by means of a Ffowcs-Williams and Hawkings integral solution. The simulated acoustic far field results and boundary layer characteristics for the teeth configuration match earlier experiments well. Furthermore, the numerical results confirm that the combed teeth give a larger noise reduction than the standard teeth. It is hypothesized that the main noise-suppression mechanism of the combs is an improvement in the streamline angles: in general, the flow tends to be less three-dimensional and more aligned with the serration edge. As a result, less vorticity is produced, especially at the root of the serrations.
Original language | English |
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Title of host publication | 35th Wind Energy Symposium, 2017 |
Publisher | American Institute of Aeronautics and Astronautics Inc. (AIAA) |
Number of pages | 24 |
ISBN (Electronic) | 978-1-62410-456-5 |
DOIs | |
Publication status | Published - 2017 |
Event | 35th Wind Energy Symposium - Grapevine, United States Duration: 9 Jan 2017 → 13 Jan 2017 Conference number: 35 http://arc.aiaa.org/doi/book/10.2514/MWES17 |
Conference
Conference | 35th Wind Energy Symposium |
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Country/Territory | United States |
City | Grapevine |
Period | 9/01/17 → 13/01/17 |
Internet address |