Characterization of the Leading-Edge Erosion of Wind Turbine Blades by Sand Particles Impingement

Solid particle erosion experiments have been conducted on the leading-edge of a wind turbine blade with silica sand as the abrasive material. Two variables have been investigated in this experiment: the angle of attack at which particles impact the leading-edge and the erosion duration. For the angle of attack, four angles of attack have been used, namely: −5°, 0°, 5°, and 10°, and for erosion duration, 180 seconds and 360 seconds were used. Two parameters have been used to analyze the erosion behavior: the amount of material removed and the erosion scars’ depth. Then, to record the change in the airfoil profile, a 3-D scanner was used before and after the erosion experiments. It has been found that, on average, the highest erosion rate and depth of erosion scars occurred at 0°, which resulted in the most alteration in the 2D profile of the airfoil, while the least damage observed was caused by 10° angle of attack. The erosion scars created by the four angles of attack were superposed to create an erosion scar similar to that created by sandstorms, extrapolated along the blade, and the total mass loss was calculated. Then, a model to estimate the amount of material removed from the leading edge of wind turbine blades using the depth of erosion scars was proposed. Finally, a preliminary aerodynamic analysis has been conducted in terms of lift and drag coefficients before and after erosion. It has been found that with the increase of intensity in erosion, the change in the aerodynamic performance increases.