A wind turbine blade leading edge rain erosion computational framework

Abstract

Blades are one of the most important components, in terms of capital and operational costs, of wind turbines. The experienced acquired by the industry in the latest decades has shown that leading edge erosion is a problem of concern that impacts the reliability of the blade and the power production of the turbine, among others. This study provides a framework to estimate leading edge erosion evolution and energy production degradation throughout time to apply in operation and maintenance decision making. It is based on the generation of synthetic wind and rain data based on observations from the site and ERA5 reanalysis data, whirling arm test data of erosion protection coatings, along with aerodynamic polar curves for clean and eroded airfoils of the blade. Rain erosion is calculated based on impingement, and assumed to be linearly accumulated using the Palmgren–Miner rule. Synthetic wind and rain time series are used to evaluate 25-year erosion degradation and energy production scenarios. A case study using the 5MW NREL’s wind turbine located in the North Sea has been analysed with the proposed framework showing maximum annual energy production losses in the range of 1.6–1.75% and first erosion failure between years 2 and 6.