Experimental assessment of a morphing trailing edge device for wind turbine blade performance improvement

Abstract

Nowadays, wind energy plays a central role in the renewable energy production, and the optimization of wind turbine performance is the focus of current research studies. In this context, morphing trailing edge system could be a promising solution to enhance wind turbine blades' aerodynamic performance. In this paper, an innovative morphing trailing edge system was designed, developed, and tested to improve the performance of a wind turbine blade airfoil. The trailing edge deformation is electrically operated through piezoelectric actuators and a compliant surface. Wind tunnel tests were performed for the sake of system validation at Reynolds number equal to 1.75×105 and 3.5×105 and an angle of attack ranging from −8° to 8°. The results put in evidence the effectiveness of the proposed morphing trailing edge system to enhance the aerodynamic performance. The trailing edge deformation allows to increase or decrease the lift coefficient. The mean percentage difference of lift coefficient was found equal to −83.6% and 68.4% for an upward and downward deflection, respectively. Meanwhile, the drag coefficient does not have a significant variation. Consequently, the aerodynamic efficiency will be increased or decreased keeping the angle of attack unchanged. The mean percentage difference of efficiency was found equal to −83.2% and 77.5% for an upward and downward deflection, respectively. In this way, it would be possible to optimize wind turbine blades' efficiency and production under different operating conditions.