Application of a Vortical Stator Assembly to Augment the Rotor Performance of Drag-Type Vertical-Axis Wind Turbines

摘要

A vortical stator assembly (VSA), surrounding a drag-type,rnvertical-axis wind turbine, was developed to improve rotor performance.rnThe VSA consisted of six guide vanes, which were to guide the airrntangentially into the VSA. The design concept was to generate a vorticalrnflow inside the VSA, to reduce the negative torque of the returning rotorrnblade, and to increase the air speed into the rotor. Wind tunnel tests werernconducted to study the VSA effects on rotor performance. Results show thatrnthe VSA significantly increased rotor performance. The augmentation ratiosrnof the rotor power outputs with the VSA were between 8.33 and 13.62rnunder the investigated wind speeds between 4 m/s and 8 m/s, and windrndirections between 0° and 50°. The diameter of the rotor integrated VSArnincreased by less than 87.5%. A yaw mechanism was not required becausernthe power augmentation with the VSA was significant regardless of windrndirection. Results also show that the rotor starting speed was reduced tornapproximately 1 m/s.