Performance Enhancement of a Savonius Vertical Axis Wind Turbine with Bio-Inspired Design Modifications

TL;DR: In this article, a Savonius-type vertical-axis wind turbine (VAWT) is proposed to improve the efficiency by incorporating the concept of dimples on the negative side of the rotor blade and tubercles on the leading edge of the turbine blade.

Abstract: One of the prime commodities in modern civilization is energy. The amount of energy consumption has become the indicator for the standard of living and the degree of industrialization. People use fossil fuels to meet nearly all of their energy needs, such as powering vehicles, producing electricity for light and heat and running factories, thus greatly exhausting the fossil fuel reserves along with polluting the environment with greenhouse gases. Renewable energy sources are viable alternatives, and among the various types of renewable energy sources available, wind energy is the sector which has a lot of untapped potential. Our objective is to improve the efficiency of a Savonius-type vertical-axis wind turbine (VAWT) which currently has the least efficiency among existing wind turbine designs. Savonius turbines have a very compact structure and can run at low wind speeds which are desirable characteristics for commercial-scale power production. This research paper focuses on improving the efficiency of Savonius wind turbine. Since Savonius-type wind turbines are drag-based wind turbines, we need to reduce the impulsive force acting on the negative face in order to increase the drag difference between the positive and negative side of the rotor blades thereby improving the efficiency of the turbine. Our proposition for attaining higher efficiency is by incorporating the concept of dimples (inspired from golf ball) on the negative side of the rotor blade and tubercles (inspired from whales) on the leading edge of the rotor blade. Dimples reduce the amount of wake region in the case of golf ball by increasing turbulence which is one of the desirable characteristics in the case of Savonius wind turbine. Tubercles help in reducing the wake region behind the rotor blades by increasing the turbulence of air near the surface of the rotor thereby improving the efficiency of the turbine.