3Ders reports on exciting new 3D printed ultra-silent turbine blades developed by a team of researchers at Iowa State University. Bharat Agrawal, Andrew Bodling, and Anupam Sharma looked to owl wings as inspiration for their blades.
Owls have incredibly quiet wings, due to their nocturnal hunting habits. Sharma, who is an Assistant Professor of Aerospace Engineering and a Walter W. Wilson Faculty Fellow lays out the three mechanisms by which owls fly so silently: “fine, comb-like structures on the leading edge of the wing; a pliable and porous fringe on feathers at the trailing edge of the wing; and a downy coat on the bird’s flight feathers.”
In order to investigate further, the team 3D scanned “various owl wing specimens, turning them into digital 3D models that can run through simulation software. This has allowed them to figure out how those three wing features affect air flow, turbulence, and pressure to produce a virtually silent motion.”
“By 3D printing airfoils with a serrated leading edge – designed to replicate the fine comb-like structures on the owl’s wing – the [researchers] found that noise was reduced significantly when compared with airfoils with a flat leading edge, also reducing the unsteady pressure on the back end of the blade surface. So even though there’s a big material difference, copying the subtle form of the owl wing has produces a comparable effect.”
As Sharma explains, these 3D printed turbine experiments “could have a big impact on the design of things like wind turbines and aircraft, which could reduce their noise emissions by implementing these owl-inspired features. The results of this research could have an impact on the design of silent air vehicles with applications in national defense, commerce, and transportation.”
The National Science Foundation is supporting these experiments further with a five-year, $500,000 CAREER grant. The Iowa Space Grant Consortium has contributed an additional $100,000 boost to the experiments as well.
Image and Quotes Courtesy of 3Ders