Influence of blade profiles on Savonius rotor performance: Numerical simulation and experimental validation

In this work, some notable blade profiles of drag-based vertical axis Savonius wind turbine rotor have been investigated both numerically and experimentally to judge their performances on a common platform. At the outset, 2D unsteady simulation is performed for semicircular, Benesh, modified Bach and elliptical profiles keeping the overall rotor diameter in each case to be constant. The simulation has been carried out using the Shear Stress Transport k-omega turbulence model with the help of the finite volume solver ANSYS Fluent. The torque and power coefficients, in each case, are estimated as a function of tip speed ratio. The total pressure, velocity magnitude, and turbulence intensity contours are obtained and analyzed. Finally, wind tunnel tests are conducted to validate the numerical results. From the numerical simulation, the maximum power coefficients for the semicircular, Benesh, modified Bach and elliptical profiles are found to be 0.272, 0.294, 0.304 and 0.34, respectively. However, the wind tunnel tests with the semicircular, Benesh, modified Bach and elliptical-bladed rotors demonstrated the maximum C-P to be 0.158, 0.159, 0.162, and 0.19, respectively.