Performance of a Vertical Axis Wind Turbine with Variable-Pitch Straight Blades utilizing a Linkage Mechanism

Abstract

This paper describes the performance of a micro vertical-axis wind turbine with variable-pitch straight blades. The proposed variable-pitch angle mechanism has an eccentric point that is different from the main rotational point. One feature of the mechanism is its ability to vary the pitch angle of the blades according to the azimuth angle of the main links, without actuators. The performance of the wind turbine was measured in an open-circuit wind tunnel. The performance of the vertical-axis wind turbine with variable-pitch straight blades was better than one with fixed-pitch blades. A wind turbine with variable-pitch straight blades has wind directivity. It was found that the performance of a wind turbine is dependent upon the blade offset pitch angle, the blade pitch angle amplitude, the size of the turbine, the number of blades, and the airfoil profile.