Effects of blade torsion on IEA 15MW turbine rotor operation

Abstract

The increase in the size of wind turbine rotors in recent decades necessitates investigations into aeroelastic behavior and its influence. This work proposes the computational modeling and the subsequent dynamic study of the rotor of the IEA Wind TCP Task 37 reference wind turbine of 15MW, considering different torsional stiffness and wind speed conditions. Sensitivity studies regarding the wind conditions and the torsional stiffness of the blades on the overall operation were carried out. It was verified that at nominal wind speed, the original torsional stiffness led to a reduction in the thrust on the rotor, the flapwise displacement at the blade tip, and the peaks of flapwise curvature at the blade root compared to the amplified stiffness. Referring to different wind speeds, simulations using the original torsion stiffness revealed a considerable decrease in generator torque with the expected in the high wind speed region, in contrast to the amplified stiffness. It is also noteworthy that the peak shaving process is affected by the amplified blade torsional stiffness, as it can lead to excessive adjustments due to smaller cut regions and thrust values. Consequently, a new pitch curve was proposed, taking into account the desired generator torque.