Investigation of the Leading-Edge Erosion of Wind Turbine Blades Using Multivariant Analysis Method

Abstract

With the vast development in the wind energy industry, new climates that might be considered harsh on wind turbines are being investigated. One such harsh climate is the desert and arid climate with the high frequency of sandstorm occurrences. During a sandstorm, sand particles of different sizes and shapes collide with wind turbine blades at different angles of attack and impact velocities, causing enormous damage, especially at the leading-edge area. The leading-edge erosion causes a drastic decrease in the turbine’s overall efficiency and, consequently, the amount of energy produced. In this paper, a multiple regression statistical study was conducted to investigate the effects of variables such as air pressure (consequently the particle impact velocity), erosion duration, and the angle of attack. These three variables were used to imitate the conditions during sandstorms closely. The outcome of the erosion process is measured in terms of mass loss and depth of erosion scars. The resulting damage from the erosion process was analyzed using the Analysis of Variables (ANOVA) method. It has been found that the angle of attack has a significant effect on the erosion behavior, with the most severe damage occurring at a 0° angle of attack for both the amount of mass loss and the depth of erosion scars, while the lowest amount of damage occurring at a 10° angle of attack. Similarly, increasing impact velocity and erosion duration caused the most severe damage, and these variables were used to characterize the behavior of the leading-edge erosion of wind turbine blades. Therefore, designers of wind farms in the desert must bear in mind that it is of extreme importance to study probability of sandstorms occurrence, their average duration, their occurrence frequency, and the particles’ velocity.