Abstract
Attenuation of self-excited roll oscillations of low-aspect-ratio wings using acoustic excitation was studied in a wind tunnel. For a rectangular flat-plate wing with an aspect ratio of 2, roll oscillations can be completely suppressed, and the onset of the roll oscillations can be delayed with external acoustic excitation. Similar results were also obtained for wings with two different airfoil profiles. Velocity measurements indicated that acoustic excitation could restore a symmetric vortex flow over the free-to-roll wings, thus eliminating the self-excited roll oscillations. The effect of excitation is most noticeable for the side of the wing that sees a larger effective angle of attack due to the rolling motion. Acoustic excitation energizes the shear-layer instabilities and results in reattachment or smaller separated flow region closer to wing surface, thus in turn suppressing the roll oscillations.
Original language | English |
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Pages (from-to) | 843-854 |
Number of pages | 12 |
Journal | AIAA Journal |
Volume | 52 |
Issue number | 4 |
DOIs | |
Publication status | Published - 1 Apr 2014 |
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Dive into the research topics of 'Attenuation of self-excited roll oscillations of low-aspect-ratio wings by using acoustic forcing'. Together they form a unique fingerprint.Profiles
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Ismet Gursul
- Department of Mechanical Engineering - Emeritus Professor
Person: Honorary / Visiting Staff
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Zhijin Wang
- Department of Mechanical Engineering - Senior Lecturer
- IAAPS: Propulsion and Mobility
Person: Research & Teaching, Core staff