Computer Analysis of S822 Aerofoil Section for Blades of Small Wind Turbines at Low Wind Speed

The power generated in wind turbine depends on wind speed and parameters of blade geometry like aerofoil shape, blade radius, chord length, pitch angle, solidity, etc. Aerofoil selection is the crucial factor in establishing the efficient wind turbine. More than one aerofoil in a blade can increase the efficiency further. Previous studies of different aerofoils have shown that efficiency of small scale wind turbine increases when NREL S822 aerofoil is used for wind speed on and above 10 m/s. This paper introduces a study on effect of low wind speed (V = 5 m/s) on performance of blade profile. Aerofoils NREL S822/S823 are used for microwind turbine with S823 near root and S822 near tip. Blade of 3 m radius with spherical tubercles over entire span is analyzed considering 5 deg angle of attack. The computational fluid dynamics (CFD) simulation was carried out using ANSYS fluent to study the behavior of blade profile at various contours. The study shows that blade experiences maximum turbulence and minimum pressure near trailing edge of the tip of blade. The region also experiences maximum velocity of the flow. These factors result in pushing the aerofoil in upward direction for starting the wind turbine to rotate at the speed as low as 5 m/s.