By getting up close and personal with the intricate mechanical structures of birds flying, scientists are constantly unsealing the secrets that can help them pursue advanced aerodynamics, which may include aircraft that produce less noise. By simulating the microstructure of owl feathers, scientists in Europe are developing a new type of aircraft wing that they say could yield important gains in this area.
The innovation, by researchers at City University of London and the Aachen University of Technology in Germany, revealed the role of microstructures at the forehead of owl feathers, known as finlets. The scientists first collected 3D geometric data on typical owl feathers using high-resolution microCT scans, creating a digital model that could be studied by calculating fluid dynamics.
This reveals that the role of these microstructages is to re-direct air flow and make it appear more coherent. Inspired by microstructurs, the team built an expanded wing and tested it in a water tunnel, which again showed that they could reboot and stabilize the flow of air through them.
The result is contrary to the team’s expectation that the curvature of this microstructure will actually produce a micro-vortex. Instead, they found that they acted together as thin conduits, smoothing the span of the wings and allowing owls to move quietly through the air.
Based on this basic model, the team plans to develop a technical version of the wing, which will be used to further study the acoustic effects of flight in wind tunnel testing. Ultimately, our goal is to apply these types of microstructages to advanced aircraft wing designs, with the potential to reduce the noise they produce.
The study was published in the journal Biological Inspiration and Bionics.