Attenuation of self-excited roll oscillations of low-aspect-ratio wings by using acoustic forcing

Research output: Contribution to journalArticle

10 Citations (Scopus)
72 Downloads (Pure)

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 languageEnglish
Pages (from-to)843-854
Number of pages12
JournalAIAA Journal
Volume52
Issue number4
DOIs
Publication statusPublished - 1 Apr 2014

Fingerprint

Low aspect ratio wings
Acoustics
Angle of attack
Airfoils
Velocity measurement
Wind tunnels
Aspect ratio
Vortex flow

Cite this

Attenuation of self-excited roll oscillations of low-aspect-ratio wings by using acoustic forcing. / Hu, T.; Wang, Z.; Gursul, I.

In: AIAA Journal, Vol. 52, No. 4, 01.04.2014, p. 843-854.

Research output: Contribution to journalArticle

@article{6d21726767304035832c50ecc1ea2f11,
title = "Attenuation of self-excited roll oscillations of low-aspect-ratio wings by using acoustic forcing",
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.",
author = "T. Hu and Z. Wang and I. Gursul",
year = "2014",
month = "4",
day = "1",
doi = "10.2514/1.J052689",
language = "English",
volume = "52",
pages = "843--854",
journal = "AIAA Journal",
issn = "0001-1452",
publisher = "American Institute of Aeronautics and Astronautics Inc.",
number = "4",

}

TY - JOUR

T1 - Attenuation of self-excited roll oscillations of low-aspect-ratio wings by using acoustic forcing

AU - Hu, T.

AU - Wang, Z.

AU - Gursul, I.

PY - 2014/4/1

Y1 - 2014/4/1

N2 - 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.

AB - 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.

UR - http://www.scopus.com/inward/record.url?scp=84896939632&partnerID=8YFLogxK

UR - http://dx.doi.org/10.2514/1.J052689

U2 - 10.2514/1.J052689

DO - 10.2514/1.J052689

M3 - Article

VL - 52

SP - 843

EP - 854

JO - AIAA Journal

JF - AIAA Journal

SN - 0001-1452

IS - 4

ER -