Raptor wing morphing with flight speed

Cheney, Jorn; Stevenson, Jonathan; Durston, Nicholas; Maeda, Masateru; Song, Jialei; Megson-Smith, David; Windsor, Shane; Usherwood, James; Bomphrey, Richard

Abstract

In gliding flight, birds morph their wings and tails to control their flight trajectory and speed. Using high-resolution videogrammetry, we reconstructed accurate and detailed 3D geometries of gliding flights for three raptors (barn owl, Tyto alba; tawny owl, Strix aluco, and goshawk, Accipiter gentilis). Wing shapes were highly repeatable and shoulder actuation was a key component of reconfiguring the overall planform and controlling angle of attack. The three birds shared common spanwise patterns of wing twist, an inverse-relationship between twist and peak camber, and held their wings depressed below their shoulder in an anhedral configuration. With increased speed, all three birds tended to reduce camber throughout the wing, and their wings bent in a saddle-shape pattern. A number of morphing features suggest that the coordinated movements of the wing and tail support efficient flight, and that the tail may act to modulate wing camber through indirect aeroelastic control.

Citation

Cheney, J., Stevenson, J., Durston, N., Maeda, M., Song, J., Megson-Smith, D., Windsor, S., Usherwood, J., & Bomphrey, R. (2021). Raptor wing morphing with flight speed. Journal of the Royal Society, Interface, Article 20210349. https://doi.org/10.1098/rsif.2021.0349

• Journal Article Type: Article
• Acceptance Date: Jun 21, 2021
• Publication Date: Jul 14, 2021
• Deposit Date: Jun 23, 2021
• Publicly Available Date: Jul 14, 2021
• Journal: Journal of the Royal Society, Interface
• Print ISSN: 1742-5689
• Electronic ISSN: 1742-5662
• Publisher: The Royal Society
• Peer Reviewed: Peer Reviewed
• Article Number: 20210349
• DOI: https://doi.org/10.1098/rsif.2021.0349
• Keywords: wing morphing, bird wings, 3D reconstruction, bird aerodynamics
• Public URL: https://rvc-repository.worktribe.com/output/1548613