CFD simulation of two-bucket Savonius turbine with NACA 0012 airfoil stator vanes

Abstract

To mitigate against the effect of urbanization on the ecosystem, the need for an alternative and renewable source of energy is paramount. This has resulted in increased popularity of wind turbines. Savonius wind turbine is a seamless solution for the urban environment where the wind level is low and unsteady. But, the drawback to this kind of wind turbines is the low coefficient of power. In this thesis, an attempt was made to improve the performance of the Savonius turbine by the addition of stator vanes. The current study utilizes CFD simulation to analyze the flow within a conventional Savonius rotor and the stator vaned configuration; to help identify the phenomena affecting the performance of the Savonius rotor. Although the addition of the stator did not improve the performance of the Savonius rotor, one key novelty that can be used to improve the performance of the Savonius turbine was observed. The key novelty was that the use of the downstream stator vanes as was implemented in this study, extends flow attachment on the convex side of the rotor bucket to angle of 180°. On the downside, the observation was that the upstream vanes as implemented in this study, resulted in a reduced rotor bucket performance by reducing the flow attachments to the buckets’ convex sides.