U.S. and Chilean researchers join to study wind turbine vibration, dampen unwanted noise.
Virginia Tech — March 30, 2015
Newswise — Wind turbines provide clean, abundant energy and bolster America’s power grid. But across the world people are banding together to fight wind farms, blaming noise for interrupted sleep and a host of health problems.
Scientists lack sufficient understanding of wind turbines’ noise and best ways to mitigate the effects, says Jorge Arenas, a faculty member in the Universidad Austral de Chile’s College of Engineering Sciences and director of its Institute of Acoustics.
Noise is annoying and, worse, linked to health problems, many researchers say. A newspaper in the U.K. captures the sensation: “Residents near some wind farms have likened the noise to a cement-mixer or a shoe stuck in a tumble-dryer,” writes energy editor Emily Gosden in a story in The Telegraph.
“The noise from wind turbines is not very loud,” says Virginia Tech’s Richardo Burdisso, a professor of mechanical engineering and Arenas’ colleague in Blacksburg. “However, it is annoying because of its amplitude modulated characteristic. That is, the noise fluctuates in levels with a period of 0.7 to 1.5 seconds, depending on the size of the turbine. The fluctuation in levels can be as high as 10 to 12 decibels.”
Arenas and Virginia Tech colleagues who are known for their wind tunnel research will study the vibrations of wind turbines at a large Chilean wind farm along with health impacts on nearby residents. The goal is to make wind turbines more acceptable.
Last year Ohio legislators passed a law requiring wind turbine blades to be at least a quarter-mile from the nearest property line. That’s because sounds in the low frequency range can travel great distances; they “are not well attenuated by air,” Arenas says. “Low frequency noise is hard to mitigate.” Continue reading here…..