Aerodynamic Sources of Acoustic Radiation from a Single MOD-2 Wind Turbine

Results are presented of an extensive acoustic measurement program conducted recently using one of the MOD-2 wind turbines in the DOE/NASA/BPA cluster at Goodnoe Hills, Washington. A summary of low-frequency acoustic emission characteristics is also presented. The MOD-2 acoustic emissions are compared with other large-scale turbines, including the DOE/NASA MOD-OA, the MOD-1 horizontal-axis, andthe DOE/Sandia vertical-axis designs. The unsteady aerodynamic forcing, in response to certain freestream turbulence characteristics, is identified as the source of observed acoustic and rotor aeroelastic responses.