Performance Investigation of Savonius Hydrokinetic Rotor with Novel Blades Featuring Surface Square Collars and Rectangular Edge Waves

The current work's objective is to investigate how the Savonius rotor performs in relation to the surface square collars and rectangular waves. The experimental study was carried out for three different blade profiles: conventional semicircular blade, semicircular blade with hollow collars, and semicircular blade with closed collars. The results indicate that the rotor with hollow collars outperforms the rotors other two blade profiles. The rotor’s highest coefficient of power with hollow collars is 6.68 % and 13.80 % higher than the semicircular bladed conventional rotor and the rotor with closed collars, respectively. This optimized blade was further investigated for different rectangular waves provided between two consecutive collars on the outer side and the inner side. The investigation reveals that the rotor's highest coefficient of power with 0.11 depth to pitch ratio at the outer edge is 13.36 % and 6.28 % higher than the conventional rotor and rotor with 0 depth to pitch ratio respectively, while the highest coefficient of power achieved for the rotor with 0.22 depth to pitch ratio at the inner edge is 14.98% and 7.78 % higher than the conventional rotor and rotor with 0 depth to pitch ratio, respectively.