Numerical Analysis of Modified Savonius Wind Turbine Blade with Overlap Ratio Variations

Savonius wind turbine is a type of vertical axis wind turbine (VAWT) which converts wind energy from all wind directions. Savonius turbines are appropriate to be applied to urban areas with low wind velocity. Other advantages of the Savonius turbine are the ability to operate in turbulence intensity and to self-start at low wind speeds. Wind conditions in urban areas reduce the performance of the Savonius wind turbine. This study aims to determine the effect of blade modification on the performance of the Savonius wind turbine by varying the overlap ratio (OR) applied in urban areas. This study uses Computational Fluid Dynamics (CFD) as a numerical method to model and simulate flow using OpenFOAM. The transient model simulation using pimpleFoam. The overlap ratio variations used are overlap ratio 0.0 and OR 0.15. The wind speed used for the simulation is 2.9 m/s and the simulation is for four turbine revolutions. Performance of Savonius turbines can be evaluated using coefficient of power, contour velocity, and contour pressure. The results show the coefficient of power value has increased by 30% at OR 0.15.