Experimental Investigation of the Effects of Leading-Edge Serration on the Blades of Savonius Wind Turbine

The noise of wind turbines is mainly of aerodynamic origin and is caused by the impact of the flow on the turbine blade. Therefore, improving the behaviour of the flow around the turbine and reducing aeronoise can result in reducing its annoying noise. In the first step of this research, a suitable serration is selected according to the physics of the flow, and then it is installed on the leading edge of the blade in such a way that it does not cause the power loss of the turbine. All the studies have been done experimentally in the wind tunnel and with the help of power, pressure and air velocity measurements in the wake and in the different free stream velocities. The results showed that the pressure fluctuations in the model equipped with a serrated blade have decreased by 4-9% on average in different areas compared to the simple Savonius. On the other hand, the results of the frequency analysis of the anemometer sensors also showed that in the dominant frequencies, the serration caused the range of phenomena to decrease. These results were obtained in such a way that the power measurement showed that the maximum power value of the turbine equipped with serrated blade experienced an increase of nearly 19%. On the other hand, the velocity profile in the wake also shows a greater deficit in the flow around the modified Savonius, which confirms the decrease in the output momentum from the turbine and consequently the increase in power.