Renewable Energy, vol.197, pp.1163-1173, 2022 (SCI-Expanded)
© 2022 Elsevier LtdThe efficiency of wind turbines can negatively be affected by flow structures such as the formation of laminar separation bubble or abrupt stall. This can decrease the aerodynamic performance and cause flow-induced vibration and aerodynamic noises to occur. On behalf of hinder of these situations, recent advances have been investigated on a new turbine blade concept such as utilizing continuous morphing shape. In this paper, the effects of employing a local membrane material on the suction surface of a WASP airfoil at Re = 3.5 × 104, Re = 7 × 104, and various angles of attack were experimentally investigated. Experimental results revealed that employing a local flexible membrane over the suction surface positively affected the formation of the bubble by mitigating its size and height between α = 0° and α = 8°. Additionally, power spectrum densities belonging to the power efficiency graphs showed that utilizing local flexibility caused the effects of fluctuations owing to vortex-induced vibrations to reduce, resulting in existing less vibration over the WASP airfoil. These results suggested that employing local flexible structures over the surface of thinner and less camber airfoil ensured the external loads because of vortex-induced vibrations to drop rather than the increment of the aerodynamic performance of airfoil, especially at moderate angles of attack.