Unsteady Aerodynamics of Nonslender Delta Wings

I Gursul, R Gordnier, M Visbal

Research output: Contribution to journalArticlepeer-review

269 Citations (SciVal)
379 Downloads (Pure)


Unsteady aerodynamics of nonslender delta wings, covering topics of shear layer instabilities, structure of nonslender vortices, breakdown, maneuvering wings, and fluid/structure interactions, are reviewed in this paper. Vortical flows develop at very low angles of attack, and form close to the wing surface. This results in strong interactions with the upper-surface boundary layer and in a pronounced dependence of the flow structure on Reynolds number. Vortex breakdown is observed to be much less abrupt compared to breakdown over slender wings. This results in challenges for the precise determination of vortex breakdown location and the interpretation of flow visualizations. One of the distinct features of nonslender wings is the location of the primary attachment zone outboard of the symmetry plane. Reattachment location correlates with the wing stall process and increased buffeting. Dramatic fluid/structure interactions emerge with increasing wing flexibility and result in substantial lift enhancement in the post-stall region. This recently discovered phenomenon appears to be a feature of nonslender wings. Rigid delta wings undergoing small amplitude oscillations in the post-stall region exhibit many similarities to flexible wings, including reattachment and re-formation of the leading-edge vortices. Unusual self-excited roll oscillations have also been observed for free-to-roll nonslender wings.
Original languageEnglish
Pages (from-to)515-557
Number of pages43
JournalProgress in Aerospace Sciences
Issue number7
Publication statusPublished - 2005


Dive into the research topics of 'Unsteady Aerodynamics of Nonslender Delta Wings'. Together they form a unique fingerprint.

Cite this