Abstract
This paper describes the performance of a H-type Darriues wind turbine with variable-pitch.Our aim is to get basic data to increase the efficiency of small vertical axis wind turbine system by variable-pitch mechanism.The proposed variable-pitch angle mechanism is the four-bar linkage. The feature of the variable-pitch mechanism is to be able to change pitch angles according to the rotational angles of the blades without actuators and the attack of angle of blades become a suitable value.We measured the performance of wind turbines with a NACA634-221 airfoil sections by using a wind tunnel.The performance of wind turbine is dependent on the size of turbine, it was found that efficiency of turbine increased and the wind velocity of self-start decreased than that of the fixed-pitch wind turbine by variable-pitch mechanism.
