Aerodynamic Effects of Painted Surface Roughness on Wind Turbine Blade Performance

This paper briefly examines the aerodynamic effects of typical wind turbine blade roughness by investigating an appropriate scaling criteria which best relates the roughness configuration to the resulting changes in aerodynamic forces and transition. The wind tunnel test results of two wind turbine blade sections tested with three different roughness samples are presented. The two models, consisting of a 457mm-chord and 800mm-chord airfoils using the DU96-W-180 profile, were tested in the Virginia Tech Stability Wind Tunnel at free-stream Reynolds number based on the chord between 1.5 and 3M. Preliminary analysis of the lift and drag scaling are presented as well as a sample of the transition results.