Aerodynamic Impact of Erosion

Wind turbines are designed to operate for at least 20 years and to always operate efficiently. For this reason, aerodynamic wind turbine rotor designers have ensured for many decades that the rotors can operate in a reliable way, even if the leading edges of blades are contaminated with, for example, bugs, dust or pollen. It has, therefore, been important to investigate the performance of each blade section – the aerofoils – with and without leading-edge roughness. From around 2010 there has been an increasing focus on the performance of wind turbine blades with eroded leading edges. Such erosion can appear simply by rain hitting the blade leading edge. The exact performance loss from wind turbines with eroded leading edges is neither easily predicted nor easily measured. This article describes how DTU Wind and Energy Systems in Denmark in collaboration with many companies and researchers tries to handle this issue.