Silencing wind turbines is the aim of a new project at the University of Adelaide.
Engineers are studying the causes of turbine noise to make them quieter and solve the problem of `wind turbine syndrome’.
They want to understand how air turbulence and the blade edge, or boundary layer, interact to make the noise louder than it could be.
A computer model will predict the noise output from wind farms so the team can accurately and quickly assess the effectiveness of noise-reducing designs and control methods.
Research leader Dr Con Doolan, of the University’s School of Mechanical Engineering, said the noise generated from wind turbines was “trailing edge or airfoil noise” – the same sort of noise generated at the edge of aircraft wings.
“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,” he said.
Dr Doolan said further complicating factors came from the way the noise increases and decreases as the blades rotate.
The computer model will look at the noise from the whole wind turbine and how multiple numbers of wind turbines together, as in a wind farm, generate noise.
“Wind turbine noise is very directional. Someone living at the base might not have a problem but two kilometres away, it might be keeping them awake at night,” Dr Doolan said.
“Likewise this broadband `hissing’ noise modulates up and down as the blades rotate and we think that’s what makes it so annoying.
“Wind turbine noise is controversial but there’s no doubt that there is noise and that it seems to be more annoying than other types of noise at the same level. Finding ways of controlling and reducing this noise will help us make the most of this very effective means of generating large amounts of electricity with next to zero carbon emissions.”