Experimental Study of The Effects of Blade Twist on the Performance of Savonius Water Turbine in Water Pipe

Abstract

The investigation of Savonius turbine for water application is still a bit left behind compared to the Savonius wind turbine. From this view, this investigation and development needs to be exhaustively carried out, give that Savonius has a promising potential for renewable energy. The major objective of this study was to investigate the effect of twist angles (α) on the horizontal axis Savonius rotor in the generation of electric power. The rotor is designed with two blades and endplates. The experiments were conducted on apparatus tests with twist angles of 0°, 12.5°, 30°, 45°, and 60°. From the experimental results and analyses, it was observed that the coefficient of performance (Cp) on twisted Savonius blades surpassed the rotor with without twists (α=0°)for discharge range from 2.95 x 10-3 m3/s to 8.16 x 10-3m3/s. However, at a higher discharge 11.9 x 10-3m3/s, the coefficient of performance of the twisted blades was lower than the rotor with without twists. Therefore, it can be concluded that twisted Savonius rotors are more efficient in terms of Cp at the discharge under or equal to 8.16 x 10-3 m3/s. Whereas, at a higher discharge, the performance of the twisted blades is decreased compared to those without twists. Further improvements have to be put in place to increase the efficiency of twisted horizontal axis Savonius rotor.