Wind Turbine Wake Vortex Influence on Safety of Small Rotorcraft

Kurzfassung

The wake vortex of lifting surfaces such as wind turbine blades or fixed-wing aircraft can heavily affect the blade aerodynamics of rotating wing aircraft. Based on blade element theo-ry the pilot controls required to mitigate such vortex effects are estimated and compared to the available control margin at the operating condition of interest. Contrary, when no pilot action is performed, the rotor blade flapping caused by the vortex are evaluated and compared to available margins. A concern of safety arises when the remaining margins become zero. The influence of the vortex strength, its core radius and orientation to the rotor disk are evaluated and the effect of rotor blade characteristics (Lock number, natural frequency) is investigated.