Performance study of ducted nozzle Savonius water turbine, comparison with conventional Savonius turbine

Savonius turbine presents an attractive, environmentally friendly and cost effective electric generation in low velocity regions. However, this turbine has not been fully explored, as researchers are still searching for solution for the main problem of low efficiency of Savonius turbine configuration. This research paper proposes a novel system of ducted nozzle configuration around Savonius rotor to increase the efficiency of the turbine. In this study, six different duct nozzle designs had been investigated. A numerical investigation was carried out in this research work using finite volume Reynolds-Averaged Navier-Stokes Equations (RANSE) code ANSYS Fluent with Reynolds numbers of 1.32×105. Consequently, validation was carried out following previous experiments. Flow characteristics through augmented configuration, and performance of the Savonius turbine had been studied, and it was found that the water flow speed had been enhanced by the developed ducted nozzle system. The maximum power coefficient of the ducted nozzle turbine was increased by 78% compared to the conventional modified rotor. The maximum power coefficient was 0.25 at tip speed ratio (TSR) of 0.73. The use of this system is expected to contribute towards a more efficient utilization of flows in rivers and channels for electrical generation in rural areas. •Savonius turbine suffers low efficiency problem.•This research paper proposes a novel system of ducted nozzle configuration around Savonius rotor.•In this study, six different duct nozzle designs had been investigated numerically.•The ducted nozzle shields the returning blade, thus reducing the reversing torque of the turbine.•The maximum power coefficient of the ducted nozzle turbine was increased by 78% compared to the conventional rotor.