Owls’ wings could provide the inspiration for a new generation of quieter aircraft and wind turbines according to a study carried out by researchers from Japan and China.

Published in the Institute of Physics journal, Bioinspiration and Biomimetics the research shows how the serrations on the leading edge of an owl’s wing are key to its stealthy, silent flight. A similar mechanism could be used, it is claimed, to develop mechanisms for noise suppression in wind turbines, aircraft, multi-rotor drones and other machines.
Lead author of the report Professor Hao Liu, from Chiba University, Japan, said: “Owls are known for silent flight, owing to their unique wing features, which are normally characterised by leading-edge serrations, trailing-edge fringes and velvet-like surfaces. We wanted to understand how these features affect aerodynamic force production and noise reduction, and whether they could be applied elsewhere.”
The researchers analysed owl-inspired feather wing models with and without leading edge serrations, by combining large-eddy simulations – a mathematical model for turbulence used in computational fluid dynamics to simulate air flows – and Particle-Image Velocimetry (PIV) and force measurements in a low-speed wind tunnel.
They discovered leading-edge serrations can passively control the transition between laminar, or streamline airflow, and turbulent air flow over the upper wing surface, at angles of attack (AoA) between zero and 20 degrees. This means they play a crucial role in aerodynamic force and sound production.
“These owl-inspired leading edge serrations, if applied to wind turbine blades, aircraft wings or drone rotors, could provide a useful biomimetic design for flow control and noise reduction,” said Professor Liu.
So a bit like the turbulators used on glider wings for decades, to tip the flow from laminar to turbulent, so it stays attached to the wing and not cause a separation bubble leading to increased drag and noise?
NT correctness contrarian censored again! :: large-eddy simulations implausible for bounded contrail microstructure at realistic Reynolds for “turbines & aircraft”. Moreover vorticitation variant already assessed amongst many more since earliest era in aerodynamics, with tabs & ribs & perforations as familiar formulations…
Before Prof. Liu, quite many have studied the silent flight of the owl and concept of leading edge as well as training edge serrations is not new, either !
To cite a few older studies, regardless of the countless recent studies (the subject has become very popular recently):
Graham R. The silent flight of owls. J Roy Aero Soc. 1934; 38:837–843.
Adams, H.L., Noiseless Device, US patent: 2071012
Neuhaus W, Bretting H, Schweizer B. Morphologische und funktionelle Untersuchungen über den lautlosen Flug der Eule (Strix aluco) im Vergleich zum Flug der Ente (Anas plathyrhynchos) Biol Zentr Bl. 1973;92:495–512.
Geoffrey Lilley. “A study of the silent flight of the owl”, 4th AIAA/CEAS Aeroacoustics Conference, AIAA Paper 1998-2340
Hersh A, Soderman P, Hayden R. Investigation of acoustic effects of leading-edge serrations on airfoils. J Aircr. 1974;11:197–202.