Abstract
In order to improve the aerodynamic performance of vertical axis wind turbines (VAWT), effects of pitch angle of rotor blades were numerically investigated. To solve the complicated turbulent flow field around moving airfoils with small computers, discreet vortex methods were utilized. The numerical result shows that the pitch angle is important factor to improve the aerodynamic performance. In the case of pitch angle is 1 degree, an angle of attack becomes small at upwind position of the rotor blade, and therefore, flow separation is restrained at upwind part of the VAWT. As a result, the power coefficient is 10 % larger than that of the conventional (pitch angel is 0 degree) VAWT.
