Effects of hydrometeor droplet characteristics on wind turbine blade leading edge erosion: A numerical study

Leading edge erosion of wind turbine blades is a significant source of loss of energy production in some wind farms. The extent of erosion appears to be controlled, at least in part by local meteorological conditions; specifically, by the accumulated kinetic energy transfer from collisions with falling hydrometeors (precipitation). However, the aerodynamics of flow around wind turbine blades means not all falling hydrometeors will impact the blade, and at least in principle some will be sufficiently small to follow the streamlines and thus avoid collisions with the rotating blades. Here we present the setup for computational fluid dynamics (CFD) simulations designed to quantify collision efficiency as a function of hydrometeor size for a simplified three-blade turbine using ANSYS Fluent 19.2 as the main numerical solver. The simulations correctly reproduce the pressure variability across the blade and illustrate that the variations in the droplet-blade collision probability is a function of wind speed, rain intensity and droplet diameter.