Experimental and Theoretical Study on the Aerodynamic Performance of a Small Horizontal Axis Wind Turbine

An upwind, three-bladed small horizontal axis wind turbine (HAWT) with a rotor of 2.2 m in diameter is tested in the Boundary Layer Wind Tunnel Laboratory II (BLWTL II). The power output of the turbine is measured for free stream velocities ranging from 1 m/s to 9 m/s. The blade element momentum (BEM) theory is implemented to predict the power curve of the HAWT. The theoretical characteristics of the turbine are discussed in terms of power and torque coefficients and the experimental results are compared to the numerical (BEM) estimation. Moreover, a force balance test is carried out on a single stationary blade for 16 angles of incidence, −6°≤α^′≤30°, and three free stream velocities, 5, 7 and 9 m/s, and integral blade aerodynamic coefficients are determined. These experimental characteristics are intended to provide a useful basis for developing an alternative computational method to use integral blade experimental aerodynamic data to predict the power curve of the wind turbine in the transition zone between dynamic stall and fully stalled regimes.