Numerical investigation of improvement of counter rotating Savonius turbines performance with curtaining and fin addition on blade

Abstract

Counter rotating Savonius wind turbine (CRSWT) is a vertical axis wind turbine (VAWT) which is appropriate for use in low-wind conditions. Experimenting to improve its performance is a difficult task because it is costly, time demanding, and complicated. CFD simulation with numerical prediction could be a good alternative. A novel change is introduced in this paper of two counter rotating Savonius wind turbines to enhance their efficiency. The suggested change includes curtain configurations as well as the insertion of fin to the blade. A CFD simulation was used to predict the effect of the proposed adjustments employing ‘ANSYS FLUENT 16′. To avoid the opposing torque to each rotor rotation, the curtain arrangements were placed in front of both rotors. The fin was adopted to take advantage of the available area in the blade for directing wind flow. The performance of the rotor when fitted with various curtain arrangements, both with and without fin, was predicted and compared to that of the conventional CRSWT. The goal of these comparisons was to improve the geometrical data of the suggested curtain arrangements as well as to investigate the influence of fin addition on the blade. With the curtain arrangement having maximum curtain blade lengths (500 mm, 550 mm) and maximum angles (50°, 30°) and the addition of only one fin, the CRSWT's maximum power coefficient increased by nearly 48 percent. The simulation findings revealed that by selecting the right curtain arrangement and adding fins to the blade, the performance of the CRSWT could be greatly improved.

Keywords

• Wind energy
• CFD simulation
• Savonius turbines
• VAWT
• Curtaining