Aerodynamic and aeroacoustic design considerations for small-scale, fixed-pitch, horizontal-axis wind turbines operating at low reynolds numbers.

Renewable energy is needed now more than ever to meet demands as conventional energy sources are being depleted. Wind energy has the potential to provide a substantial amount of renewable energy. Of increasing interest is the development of small wind turbines for residential and urban applications. In these settings, a new concern is the noise that these turbines produce due to their operation at higher rotational speeds. Experimental noise data for the NREL S823, Eppler 387, NACA 4412 and NACA 0012 2D airfoils were taken for Reynolds number from 50,000 to 200,000. From these studies, trends based upon airfoil shape were gathered and used in choosing a new airfoil for testing a new rotor design. From these trends, two new airfoils were chosen to compare to the baseline rotor that utilized the S823 airfoil. The two new rotors, each utilizing the Eppler 216 and SD 7062 airfoils, showed an increase of power production from 5-60%. These rotors were also able to decrease the generated noise by up to 9.5 dB(A).