Owl wing structure helps make airplane wings and blades quieter

Scientists have developed a coating that mimics the structure of owls’ wings and feathers. Wind tunnel tests show that the blades of windmills with the coating produce up to 10dB less noise.

That writes the University of Cambridge on its site. The researchers from the university and three American institutes wanted to know how owls can hunt almost silently. By examining the feathers of animals with high-resolution microscopy, the scientists found that the fly feathers have a downy covering, similar to the foliage of a forest seen from above. Below this plumage, the wings have another flexible comb of equidistant hairs along the front and a porous, elastic edging at the rear.

The scientists presented their research Monday at the American Institute of Aeronautics and Astronautics Aeroacoustics conference in Dallas. With the coating based on the owl wings, the wings of wind turbines, aircraft or fans can be made much quieter. Fans of computers could also benefit from it. The characteristics of the fans would not be affected, although the investigation is still in an early stage.

Initially, the researchers looked at materials such as that for a bridal veil. This material already reduced the noise of the wing surface by 30dB, but applying such a material to an aircraft wing did not seem very practical. To this end, the researchers developed a prototype of a 3D-printed plastic and tested it on a windmill blade. The printed material resulted in 10dB less noise in the wind tunnel test, with no noticeable difference in aerodynamics. The next step the researchers want to take is to coat a wind turbine standing in the field.