Abstract
The current study recommends a novel design that includes lightweight flapping gates that open when the convex side is facing the wind source in order to reduce negative torque and increase the efficiency of Savonius wind turbines. Very light leaf or torsional springs can be used to ensure that the gates close smoothly by returning them to their closed state. The efficiency of the turbine is increased when the flapping gates open because there is less drag force and resistive torque applied to the turbine shaft. Two turbines, one with the conventional shape and the other with flapping gates, were created in order to achieve this. The two turbines were then compared to one another under similar circumstances. To collect the necessary readings, an experimental setup with a variety of sensors was developed. Experiments were carried out at various air velocities to calculate the static torque coefficient and power coefficient. It was proved that the new design, which has a higher static torque and power coefficient, is more effective than the conventional design. The power coefficient increases by an average of 25% at middle speed ranges, but only by about 16.914% at higher tip speed ratios.