Relationship between Incident Angle of Wind on Rotor Blade and Output of a Drag-type Multi-blade Vertical-Axis Wind Turbine with Stationary Multi-vanes

Abstract

Drag-type vertical-axis wind turbines have a large starting torque and excellent self-starting performance, and are non-directional with respect to wind. In addition, because the maximum output occurs at a tip speed ratio of 1 or less, these turbines can be operated in a lower speed range compared with lift-type wind turbines. However, drawback of drag-type wind turbines is that their output is lower per unit sectional area than that of the lift-type wind turbines. Therefore, we have been studying the characteristics of a multi-blade drag-type vertical-axis wind turbine with stationary vanes functioning as wind direction plates. Our experimental results so far have shown that the wind turbine output is increased by using stationary vanes. In this paper, a method for calculating the output power of a multi-blade drag-type vertical-axis wind turbine with stationary vanes based on the characteristics of a single rotor blade was studied and compared with the results of wind turbine characteristics measured in a wind tunnel. In addition, the relationship between the wind incident angle of the rotor blade and the wind turbine output was examined using the proposed method for calculating wind turbine characteristics, assuming that the angle of installation of the stationary vanes are variable.