Riblet Surfaces for Improvement of Efficiency of Wind Turbines
The performance increase by using riblet-surfaces on rotor blades of a wind turbine was examined. So-called riblets are streamwise grooved surfaces which reduce the viscous drag in turbulent boundary layers. The following work gives an insight in the design of riblets, the application process on wind turbine rotor blades, the development of a new coating material and the abrasion effects over time. The design process includes wind tunnel tests of a rotor blade airfoil and 3D CFD simulations. For application of the riblets on a wind turbine rotor blade an automated painting system was used. Finally, results of in-service monitoring of wear are presented.