Experimental investigation of modified Savonius wind turbines

Abstract

This aim of this study was to experimentally characterize the performance of Savonius wind turbine. The turbine rotors were modified by varying the distances, measured from blade tip to the most concave point of rotor. To achieve this objective, the investigated parameters were shape factor, including 0.5, 0.4, 0.3, and 0.2 while the Reynolds numbers were set as 136,640 and 156,160. The results showed that the Savonius rotor performed better performance at the higher Reynold number. Also, the tip speed ratio and shape factor were found to have a strong influence on the characteristic of power coefficient. The maximum power coefficient was obtained during the tip speed ratio of 0.4-0.6 while the shape factor of 0.4 provided a better performance than other rotors. This corresponds with the modified rotor 1, having the higher power coefficient compared to conventional rotor by 6.67% and 18.75% for a Reynolds number of 136,640 and 156,160, respectively.