SUMMARY
HAWT with three blades is often used, because it has the highest power coefficient among other turbines. The airfoil used is Clark-Y type because it has high glide ratio (coefficient lift/coefficient drag) in the application of subsonic flow. The main purpose of this study is to increase the power coefficient value obtained by the increase of lift force on each airfoil of blade compiler, and to fix the wind turbine performance. One of the variations added is the addition of winglets on the tip of the blade. The method employed is laboratory scaled experiment by using Wind Tunnel. Theoretically, this study also applied Blade Element Momentum (BEM) as the calculation of each segment on airfoil, and the simulation was done by using Computational Fluid Dynamic (CFD), in order to find out the characteristics of flow passing by the rotor. The advantage of using winglets is, fostering the condition of starting wind turbine rotor on small Tip Speed Ratio (TSR) condition by varying the pitch angle on the blade. The addition of pitch variation gives an advantage that it can maximize the wind speed towards the angle of attack to airfoil, hence it increases the aerodynamic effect on the rotor.