Issues concerning roughness on wind turbine blades

This paper reviews the effects of surface roughness, accreted on wind turbine blades, on the flow field and power generation. Contamination agents, like dust, dirt, ice, and even insects accumulate on the blades and generate roughness to varying degrees. These roughness elements, depending on their size, location, and density, may disturb the flow field and reduce the power produced by the machine. A review of papers addressing similar flow patterns is provided, along with an analysis of the ability of numerical algorithms to correctly predict the power performance and the flow characteristics in the presence of surface irregularities. Finally, solutions are given to mitigate the effects of roughness on power production.