Owls` wings could hold key in making aircraft and wind turbines quieter

Tokyo: A new research suggests that the unique wing features of owls could hold the key to make aircraft and wind turbines quieter.

Researchers from Japan and China found that the serrations in the leading edge of owls’ wings, gaining new insight into how they work to make the bird’s flight silent.

The results, pointed towards potential mechanisms for noise suppression in wind turbines, aircraft, multirotor drones and other machines.

Lead author Hao Liu, Professor at Chiba University in 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.”

Liu added,“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, or PIV (an optical method of flow visualisation used in education and research), and force measurements in a low-speed wind tunnel.

They discovered leading-edge serrations can passively control the transition between laminar, or streamline air flow, and turbulent airflow 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.

Liu said,“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.”

The study was published in the journal Bioinspiration and Biomimetics.

(With IANS inputs)