Design and Wind-Tunnel Verification of Low-Noise Airfoils for Wind Turbines

A method for the prediction of the airfoil trailing-edge far-field noise is presented. The model employs the airfoil analysis code XFOIL to determine the initial and boundary conditions for a subsequent boundary-layer analysis using the finite-difference code EDDYBL featuring a Reynolds stress turbulence model that finally provides the input data for the noise prediction by a modified TNO Institute of Applied Physics model. The prediction scheme was applied in the European silent rotors by acoustic optimization project to design new, quieter airfoils for the outer blade region of three different wind turbines in the megawatt class. The objective was to reduce the airfoil self-noise without loss in aerodynamic performance