Performance Investigation of Two Vertical-Axis Twisted Rotor Models

Abstract

The world nowadays is looking for a clean source of renewable energy that produces no air or water pollution. Wind energy has become an optimal solution for world needs and the governments offer great attention to wind-energy development. In the present work, two outstanding Savonius rotor models are first investigated numerically using the three-dimensional unsteady Reynolds-averaged Navier-Stokes (URANS) equations, along with the Shear Stress Transport (SST) k-ω turbulence model. Various twist angles are trained for both rotor models and the best efficient model is further fabricated and tested experimentally using an open jet wind tunnel. The numerical and experimental results show good agreement, and the proposed rotor geometry has superior performance. The maximum power coefficient obtained for that optimum rotor is found to be 0.221 at the highest performance twist angle of 45 o . Furthermore, the proposed rotor model introduces a positive torque coefficient during the entire rotation cycle, with reduced cyclic torque.