For vertical axis wind turbines, the operation performance can be improved by changing the airfoil shape. In practice, there are many ways to control the airfoil shape of vertical axis wind turbines. One is to change the Angle of the blade according to the Angle specified by the program.
Angle of attack, push rod or eccentric CAM adjustment blades in the leaf blade shaft length direction, leaf by leaf shaft installed in the rotor blade holder, a connecting rod drive blade rotation, the connecting rod is controlled by the CAM or eccentric, also fitted with devices to the wind to make the CAM is governed by the wind, the CAM is according to the set of control law design, make the blade goes in a different location to a predetermined Angle. In this way, the vertical axis wind turbine can start itself and operate in a wide range of wind speeds.
The other is to use the wind force and block to control the Angle of the vertical axis wind turbine blade, directly push the blade oscillation by the wind force, and use the baffle to limit the Angle of oscillation. In the direction of blade length, there is the blade rotation axis. The blade rotation axis is located in the front of the pressure center of the blade. The rotation axis of the blade is set at the position of 1/4 blade chord length from the leading edge of the blade, which can ensure that the combined force of the blade at any Angle of the wind on the blade is behind the rotation axis, which can make the blade sway in the wind. This allows vertical axis wind turbines to start themselves and operate at low to high wind speeds.http://www.titanwindturbine.com/