WIND PROFILE EFFECT ON SMALL WIND TURBINE NOISE GENERATION

摘要

Small wind turbines are usually located close to buildings, and therefore, the noise generation can be both annoying and a risk for the health. The number of wind turbine installations is growing, and the request for distributed small scale energy production is one of the future trends in the energy market. The wind behavior is usually non-linear close to the ground surface. Especially, small turbines with low nacelle heights have a relatively declined wind profile at the blades. The chosen modeling approach coupled three-dimensional RANS with the Ffowcs Williams-Hawkings acoustic analogy. A series of numerical simulations was performed to study the reliability of the modeling. Three different grids were used to study the grid independency close to the turbine nominal tip to speed ratio. A reasonable agreement in the noise trends was found between the modeling and the measurements and previous studies. This encouraged us to study three different wind profiles with a down scaled wind turbine model. The results indicate that the aerodynamic noise of small turbines is not markedly affected by the wind profile.