Multielement Airfoils for Wind Turbines

The thick root airfoils of modern wind turbines, with current technology designs reaching 45% thickness, are incapable of producing high lift, and as a consequence, the blades are aerodynamically and structurally suboptimal. Additionally, the road-transportable blade length is limited to between 53 and 62. m depending on the specific blade geometry. The use of multielement airfoil arrangements on utility-scale wind turbine blades has the potential to allow for (1) improving aerodynamics near the hub section, (2) improving the structural arrangement, and (3) creating natural disconnect points that ease transportation constraints. Segmented blades are already being used by wind turbine manufacturers, including Gamesa and Enercon, to solve transportation constraints. Studies that investigated candidate multielement airfoil configurations to serve as an aerodynamic fairing for an assumed spar cap yielded promising results. The use of multielement airfoils for wind turbines can increase the blade efficiency, provide better start-up performance, and offer gross annual energy production (GAEP) benefits.