Flapping dynamics of an inverted flag

Cited 45 time in webofscience Cited 0 time in scopus
  • Hit : 381
  • Download : 0
The dynamics of an inverted flag are investigated experimentally in order to find the conditions under which self-excited flapping can occur. In contrast to a typical flag with a fixed leading edge and a free trailing edge, the inverted flag of our study has a free leading edge and a fixed trailing edge. The behaviour of the inverted flag can be classified into three regimes based on its non-dimensional bending stiffness scaled by flow velocity and flag length. Two quasi-steady regimes, straight mode and fully deflected mode, are observed, and a limit-cycle flapping mode with large amplitude appears between the two quasi-steady regimes. Bistable states are found in both straight to flapping mode transition and flapping to deflected mode transition. The effect of mass ratio, relative magnitude of flag inertia and fluid inertia, on the non-dimensional bending stiffness range for flapping is negligible, unlike the instability of the typical flag. Because of the unsteady fluid force, a flapping sheet can produce elastic strain energy several times larger than a sheet of the deformed mode, improving the conversion of fluid kinetic energy to elastic strain energy. According to the analysis of the leading-edge vortex formation process, the time scale of optimal vortex formation correlates with efficient conversion to elastic strain energy during bending.
Publisher
CAMBRIDGE UNIV PRESS
Issue Date
2013-12
Language
English
Article Type
Article
Keywords

FLOW-INDUCED VIBRATION; ENERGY HARVESTING EEL; AXIAL-FLOW; FLUTTER; PLATES; CYLINDER; MODEL; EDGES; WIND

Citation

JOURNAL OF FLUID MECHANICS, v.736

ISSN
0022-1120
DOI
2-s2.0-84887491497
URI
http://hdl.handle.net/10203/201288
Appears in Collection
ME-Journal Papers(저널논문)
Files in This Item
There are no files associated with this item.
This item is cited by other documents in WoS
⊙ Detail Information in WoSⓡ Click to see webofscience_button
⊙ Cited 45 items in WoS Click to see citing articles in records_button

qr_code

  • mendeley

    citeulike


rss_1.0 rss_2.0 atom_1.0