Researchers from the University of Adelaide’s School of Mechanical Engineering are studying the cause of windturbine noise, to make them quieter and in turn will not bother people living in the surroundings.
The Adelaide scientists, led by research leader Dr. Con Doolan, say wind turbines generate “trailing edge or airfoil noise,” the same kind of noise generated at the edge of aircraft wings. They found that wind turbine noise is very directional. Someone living at the base might not have a problem but 2 kilometers (1.2 miles) away, it might be keeping them awake at night. Known as wind turbine syndrome, the noise generated by wind turbines can affect people who are kilometres away, causing complaints including headaches, insomnia, anxiety and dizziness.
Doolan and his team are now developing a computer model to predict the noise output from wind farms so they can accurately and quickly assess the effectiveness of noise-reducing designs and control methods. He explains: “”We know generally what causes that noise – as the turbulent air flows over the sharp edge of the blade it radiates sound much more efficiently, so the noise can be heard at some distance. What we don’t yet understand, however, is exactly how that turbulence and blade edge, or boundary layer, interact and how that makes the noise louder.
“If we can understand this fundamental science, we can then look at ways of controlling the noise, through changing the shape of the rotor blades or using active control devices at the blade edges to disrupt the pattern of turbulence and so reduce the noise.” He adds: “as we move towards more renewable energy sources, we can expect to see more wind farms in the future. That means more people will be exposed to wind farms, so we need to understand why some people are more affected than others. With the right funding we could get some definitive results in two to three years which will help us plan better wind farms in the future.”
via: ABC Science