The Springer Model for Lifetime Prediction of Wind Turbine Blade Leading Edge Protection Systems: A Review and Sensitivity Study.

Nick Hoksbergen,Remko Akkerman,Ismet Baran

doi:10.3390/ma15031170

Abstract

The wind energy sector is growing rapidly. Wind turbines are increasing in size, leading to higher tip velocities. The leading edges of the blades interact with rain droplets, causing erosion damage over time. In order to mitigate the erosion, coating materials are required to protect the blades. To predict the fatigue lifetime of coated substrates, the Springer model is often used. The current work summarizes the research performed using this model in the wind energy sector and studies the sensitivity of the model to its input parameters. It is shown that the Springer model highly depends on the Poisson ratio, the strength values of the coating and the empirically fitted constant. The assumptions made in the Springer model are not physically representative, and we reasoned that more modern methods are required to accurately predict coating lifetimes. The proposed framework is split into three parts—(1) a contact pressure model, (2) a coating stress model and (3) a fatigue strength model—which overall is sufficient to capture the underlying physics during rain erosion of wind turbine blades. Possible improvements to each of the individual aspects of the framework are proposed.

Highlights

Global climate accords demand lower CO2 emissions
In order to compute the lifetimes according to the Springer model, an impact velocity (V) of 100 ms−1, a droplet diameter (d) of 2 mm and a coating thickness (h) of 750 μm were considered
This last observation raises the question of how the Springer model responds to variations in its input parameters, and a sensitivity study was performed

Summary

Introduction

Global climate accords demand lower CO2 emissions. Production of renewable energy using wind turbines shows high potential towards achieving these goals. In order to produce more energy from wind turbine blades, they are being made larger and currently exceed 200 m in diameter. These large wind turbines are prone to different types of damage [1,2]. The erosion damage, as shown, leads to a decrease in aerodynamic efficiency and a reduction in annual energy production (AEP) [4,5,6]. Leading edge protection (LEP) systems have been developed that consist of erosion resistant materials to elongate maintenance intervals [8] while limiting the AEP loss [9]. A commonly used model to estimate the lifetime of such LEP systems was developed by Springer [10]

Results

Discussion

Conclusion