Owl-like wing design could mitigate wind turbine noise

New Scientist : To reduce the noise created by wind turbines, researchers have proposed modifying the blades to mimic owls’ wings. Owls are well known for their ability to fly silently. Nigel Peake of the University of Cambridge and his colleagues found that the wings of owls, unlike those of other birds, have evenly spaced bristly feathers that are serrated along their leading edge, which breaks up air turbulence and reduces the whooshing sounds made by the wings as they move through the air. The owls’ down also provides a dampening effect by reducing air pressure on the surface. The researchers replicated those features through the use of comblike fins that are spaced about 1 mm apart and trail off the turbine blade’s edge. Because many wind turbines are braked to reduce noise, the modified blades could allow them to run faster and generate more energy.