Numerical and Experimental Study on the Savonius Rotor Performance with the Gap Width Variations of Ventilation in Middle Blades

In previous research, the use of ventilation at 15° from the outer end of the blade Savonius was able to increase the efficiency of Savonius windmill. This study aims to determine how the influence of the fixed ventilation on middle of the blade towards a performance of the Savonius windmill. There are one model of the conventional Savonius windmill and three models of the ventilated Savonius windmill that simulated by CFD and tested in the wind tunnels. Simulation variabels used are variations for ventilation width and the rotation angle position of the rotor. Experimental variables were variations for the gap width of ventilation and wind speed. The ventilated Savonius with ventilation position in the middle of the rotor blades turns out to have the average power coefficient (Cp) lower than the conventional Savonius windmill. The wider the gap from the ventilation will further reduce the performance of the ventilated Savonius rotor. In this study, the SV65-10 model produced the worst performance. This power coefficient of the SV65-10 model is 29% lower than a conventional Savonius rotor..