Effects of flow parameters on the performance of vertical axis swirling type Savonius wind turbine

Abstract

Wind tunnel experiments were carried out on a geometrically optimal swirling Savonius turbine by varying flow parameters to determine their effects on power and torque coefficients. The optimum geometrical configuration used in this experiment was adopted from an earlier study that features 0.20 blade overlap ratio, 195° blade arc angle, and 1.06 rotor aspect ratio of a 320 mm diameter rotor with closed top end plate. The parameters considered in this experiment are the hot air temperature, hot air mass flow rate, hot air inlet diameter of swirl chamber, and the free-stream wind velocity. The results indicate that higher hot air temperature and hot air mass flow rate enhance the performance of the turbine while power coefficient reached maximum at 16 mm diameter of hot air inlet. Tests on the optimum geometry at five wind velocities revealed that power coefficients are higher in higher wind velocities, which suggests that swirling flow becomes stronger with the increase of wind velocity.