Performance Analysis of a Helical Savonius Wind Turbine with Modified Rotor

Abstract

This study aims to investigate numerically the performance of a helical Savonius wind rotor with a twist angle of 45°. The twist is performed on a modified profile of the rotor blade. The power coefficient (Cp), the torque coefficient (CT), and the static torque coefficient (CTS) are computed under a constant aspect ratio of 1.0 and overlap ratio of 0.15. The numerical results presented in this paper are obtained using the three-dimensional incompressible unsteady Reynolds-Averaged Navier-Stokes equations along with the RNG k-ε turbulence model. A comparison between the present helical Savonius wind turbine of modified rotor and the helical Savonius wind turbine of conventional rotor shows better performance for the present modification. The maximum power coefficient and the maximum torque coefficient for the present helical modified rotor are 0.22 and 0.41, respectively.