Numerical simulation and aeroacoustic noise modelling of a wind turbine using a blade section in an annulus

Abstract

Noise disturbance from wind turbines is one of the major factors which slows wind farm development near populated areas. Therefore, it is important to have an accurate estimate of the noise generated before production and installation of wind turbines. Large Eddy Simulation (LES) can be used to determine the aerodynamic sound produced by a moving surface, but LES of a whole wind turbine is computationally expensive. However, Oerlemans’ field measurements show that most of the noise from wind turbines is generated at 75%-95% of the span of the blade. This suggests that simulation of a section with the most significant noise sources could lead to a useful overall noise estimate in the far field. The present work is focused on noise prediction from a wind turbine using a rotational annulus containing a section of a wind turbine blade, which leads to a significant reduction of computational expense. LES with the Ffowcs-Williams and Hawkings acoustic analogy is used to predict the far field acoustic noise. Initial results with rotational CART-2 wind turbine blade show good agreement with the available experimental data.