The effectiveness of graphene and polyurethane multilayer coating on minimizing the leading-edge erosion of wind turbine blades

• A coating made of PU/graphene layers improved erosion resistance by up to 60 %. • Leading edge damage was most severe at 0° impingement angle and least at 10°. • Coated blades showed better aerodynamic performance both before and after erosion. • The coated blade has achieved a 62 % higher lift-to-drag ratio compared to uncoated. Wind energy has been expanding in the last few decades, and the potential for building wind farms in new and harsh environments is being explored. One such harsh environment is the desert, where the collision of sand particles during sandstorms with the leading edge of wind turbine blades is expected to cause erosive damage. The leading-edge erosion of wind turbine blades has been shown to negatively affect the turbines’ aerodynamic efficiency and power generation. In this paper, the leading-edge erosion of wind turbine blades has been experimentally investigated and characterized by studying the effects of multiple variables. These variables include (i) air pressure and, subsequently, the impact velocity of the sand particles, (ii) the impingement angle at which sand particles impact the leading edge, and (iii) the effects of protective coatings. The erosion of an uncoated wind turbine blade has been compared to that of a blade coated with alternating Graphene IA-700 and Polyurethane layers. The amount of material removed, the depth of erosion scars, and the surface roughness were utilized to analyze the erosion resistance behavior of coated and uncoated wind turbine blades. It has been found that using the combination of Graphene IA-700 and Polyurethane has decreased the amount of material removed from the blade and the depth of erosion scars by as much as 60 % compared to the uncoated blade. Moreover, the aerodynamic performance of the coated and uncoated blades has been investigated. The maximum lift-to-drag ratio (Cl/Cd) max was found to be higher for the coated blade by 36 % and 62 % before and after erosion, respectively. The results shown in this paper suggest that using the combination of graphene and polyurethane coatings is a promising strategy to reduce the effects of leading-edge erosion due to sand particles’ impingement.