Experimental investigations to improve the performance of the savonius hydrokinetic turbines using wavy edge vanes

The use of renewable energy sources can aid humanity in its fight against pollution. Hydrokinetic energy is one of the most underutilised kinds of renewable energy. One of the most basic hydrokinetic turbines is the Savonius hydrokinetic turbine. In the present work, the use of wavy edges is explored to improve the performance of Savonius hydrokinetic turbines. For the Savonius turbine, the waves on the outer edge, inner edge, and both outer and inner edges were investigated experimentally. The pitch length (wave amplitude, P ) kept constant and the effect of wavelength (λ) is explored in the present work. All the experiments are conducted at constant Reynolds number. Waves on the outer edge boost the power coefficient by roughly 12 % for the specific selected instance of P/λ of 0.15, which is the maximum improvement recorded, out of investigated three broad cases. It is also observed that the waves at inner edges and both edges adversely affects the performance of the Savonius hydrokinetic turbines.