Nov 26 2010
A recent presentation titled, ‘Optimization of turbine spacing in the fully developed wind turbine array boundary layer,’ presented at the meeting of American Physical Society Division of Fluid Dynamics (DFD) in Long Beach, California brings out a new thought in spacing wind turbines during installations.
The new theory suggested by the presenters requires a 15 rotor diameter spacing between wind turbines instead of the currently prevailing 7 rotor diameters.
Charles Meneveau, a fluid dynamics student at Johns Hopkins University, and his associate Johan Meyers, from Belgium’s Leuven University, declared that they have formulated a module to compute the required optimal spacing between the wind turbines that are installed in very large wind farms. According to them, the current spacing is not sufficient and should be increased. They explained that the blades of the wind turbines twist and form purls of turbulence when they rotate thus affecting the turbines located away in downwind direction. Most of the earlier studies of the subject have utilized computer examples and explained only the stir effect of a single wind turbine on another. The presentation made by the Meneveau and his associate utilized significant amount of computer simulations and modest level of tests in a wind turbine tunnel to prove the total effects over the atmosphere due to the functioning of hundreds and thousands of wind turbines.
They explained that the power production in a large wind farm bets most on the strong winds at higher levels than the horizontal winds. They added that a 100 meter wind turbine located in a large wind farm receives its maximum power generating capability from the boundary layer of the atmosphere that lay thousands of feet above. They explained that a large wind farm with correct spacing between the wind turbines effectively changes the disorderliness of the land similar to the way a tree does on the soil and it introduces turbulence and mingles the air to bring down the useful kinetic energy from the top to the low level.