Numerical Analysis on the Flow Noise Characteristics of Savonius Wind Turbines

Noise performance of small wind turbines is critical since these are generally installed near the community. In this study, flow noise characteristics of Savonius wind turbines are numerically investigated. Flow field around the turbine are computed by solving unsteady RANS equation using CFD techniques and the radiated noise are predicted by applying acoustic analogy to the computed flow data. Parametric study is then carried out to investigate the effects of operating conditions and geometric design factors of the Savonius wind turbine. Tonal noise components with higher harmonic frequency than the BPF are identified in the predicted noise spectra from a Savonius wind turbine. The end-plates and helical blades are shown to reduce overall noise levels. These results can be used to design low-noise Savonius wind turbines.