Baltimore, US — Charles Meneveau, a US-based Johns Hopkins fluid mechanics and turbulence expert, working with a colleague in Belgium, has devised a new formula to determine better spacing for wind turbines.
‘I believe our results are quite robust. They indicate that large wind farm operators are going to have to space their turbines farther apart,’ said Meneveau, professor of Mechanical Engineering at the university’s Whiting School of Engineering.
Wind farms typically use turbines with rotor diameters of about 100 metres and are spaced about seven rotor diameters apart. But the new spacing model developed by Meneveau and Johan Meyers, an assistant professor at Katholieke Universiteit Leuven in Belgium, suggests placing wind turbines 15 rotor diameters apart actually results in more cost-efficient power generation.
Earlier computational models for large wind farm layouts were based on the wakes of single machines, while the new spacing model takes into account interaction of arrays with the entire atmospheric wind flow, says Meneveau.
Meneveau and Meyers argue that the energy generated in a large wind farm depends mainly on the strong winds that the turbulence created by the tall turbines pulls down from higher up in the atmosphere. With the correct spacing, the turbines alter the landscape to create turbulence, that helps draw more powerful kinetic energy from higher altitudes.
Further research is needed, Meneveau says, to understand how varying temperatures can affect the generation of power on large wind farms.