The rotor is the first element in the chain of functional elements of a wind turbine. Its aerodynamic and dynamic properties are therefore formative for the entire system in several respects. The rotor’s ability to convert the highest possible proportion of the wind energy flowing through the rotor’s swept area into mechanical work is obviously a direct consequence of its aerodynamic properties. The overall efficiency of the energy conversion, which is thus largely determined, is of importance for the wind turbine, as for any other regenerative energy generation system, which should not be underestimated in terms of economic efficiency.