Performance Analysis of Side-by-Side Savonius Hydrokinetic Turbines Under Different Flow Velocities

Abstract

The increasing demand for renewable energy has spurred the development of environmentally friendly technologies. Hydrokinetic turbines, which generate electricity from flowing water without dams or reservoirs, are a promising option. Among these, the Savonius turbine is ideal for low-flow conditions because of its simple design, ability to start on its own, and low maintenance needs. This study examines the performance of a side-by-side Savonius hydrokinetic turbine at inlet flow speeds of 0.2 m/s and 0.48 m/s using Computational Fluid Dynamics (CFD). The effect of TipSpeed Ratio (TSR) on performance was analyzed through the power coefficient (Cp) and moment coefficient (Cm) across a TSR range of 0.2-2.0. Transient simulations with the k-ω SST turbulence model captured unsteady flow around the rotating blades. Results show improved turbine performance with higher flow speeds. At 0.2 m/s, the maximum Cp was 0.180 at TSR = 1.0, and the highest Cm was 0.211 at TSR = 0.6. At 0.48 m/s, the maximum Cp reached 0.180 at TSR = 1.0, and the maximum Cm was 0.75 at TSR = 0.4. These results offer valuable insights for optimizing side-by-side Savonius turbines in low-flow water conditions.