Numerical modelling of the ice throw from wind turbines

Abstract

Ice throw is a significant risk factor in the vicinity of wind turbines located in cold climate areas. We present a method to estimate the ice chunk trajectories. First, similar to the common practice, only translation is accounted for and the object trajectory is determined by gravity and the aerodynamic drag force. The sensitivity of the trajectories to the launch positions, wind speed, turbine rotation and aerodynamic drag is assessed. Next, trajectory computations with six-degree-of-freedom motion are presented. The required aerodynamic forces and moments are precomputed using CFD. The results indicate that object rotation might be non-negligible when higher accuracy is needed for the trajectory estimates.