Optimization and Experimental Validation of Savonius Turbines with Integrated Deflector for Enhanced Low-Speed Hydropower Efficiency

The global energy demand continues to rise, and increasing harmful emissions from fossil fuel combustion highlight the urgent need for alternative, eco-friendly energy sources. Hydropower stands out as a promising solution, leveraging the fact that 71 % of the Earth’s surface is covered by water, allowing for energy harnessing with minimal environmental impact. Modern hydropower technologies must also be optimized to operate efficiently in low-velocity water, a common condition that typically produces low power output. Savonius turbines have been widely studied, with many efforts focusing on enhancing their performance through design modifications. However, much of this research is limited to numerical simulations only. This study seeks to address this gap by experimentally validating a new optimization process that integrates a deflector into the turbine design, first based on Computational Fluid Dynamics. Both the turbine and deflector were fabricated and tested in our water flume, with a comparative analysis conducted against the standard Savonius turbine. In addition to evaluating key experimental parameters such as torque and rotational speed at various tip speed ratios, Particle Image Velocimetry (PIV) is used to investigate the flow structure around the turbine, proving the validity of our CFD-based optimization under real-world conditions.