Performance evaluation of vent-augmented elliptical-bladed savonius rotors by numerical simulation and wind tunnel experiments

The paper reports numerical and experimental investigation of a vent-augmented elliptical-bladed Savonius rotor. In this study, the advantages of a newly developed blade profile and an augmentation technique have been combined. To begin with, the cut angle of an elliptical profile is optimized by numerical simulation using ANSYS FLUENT. Thereafter, the optimized elliptical profile is studied with vents. Initially, 2D unsteady simulation is carried out around the vented elliptical profile using Shear Stress Transport k-ω turbulence model. The torque and power coefficients are calculated at rotating condition for various tip speed ratios. The results obtained are compared with those of non-vented elliptical and semicircular profiles. Subsequently, 3D unsteady simulation is carried out with the vented and the non-vented elliptical-bladed rotor. Finally, the wind tunnel experiments are conducted to validate the 3D numerical results. For the vent-augmented elliptical-bladed rotor, the 3D numerical simulation shows a maximum power coefficient (CP) of 0.132, while the experiments demonstrate a maximum CP of 0.146 at TSR = 0.49.