On the design of horizontal axis two-bladed hinged wind turbines.

Various hinge configurations for two bladed rotors are discussed and evaluated and the conventional teeter hinge is shown to lead to non-uniform blade angular velocity in the blade tip path plane. The solution to this problem adopted for two bladed helicopter rotors, though complex, could be of interest for large wind turbines. A much simpler solution, calling for the suppression of blade flapping by passive blade cyclic pitch variation produced by a strong negative pitch/flap coupling, was found to be practical for upwind tail vane stabilized two bladed wind turbines. (from authors' abstract)