Test Stand for Rotor Blade Coating

Funding: BMWi
Partner: Fraunhofer IFAM, BASF Coating, Epurex Films, Bayer MaterialScience, cp.max Rotortechnik, GETproject, Renewably Energy Test Centre, Automation Dr. Nix
Duration: 10/2013 - 09/2016
Project volume: 1.4 Mio. Euro


Rotor blades are exposed to severe environmental conditions: rain, hail, sand, salty sea water and dirt all gather on the surfaces and lead, especially on blade leading edges, to soiling and roughening of paint and coating systems. Temperature changes and UV radiation intensify these effects. This leads to material abrasion and crack formation caused by rain erosion and in turn, results in increased deterioration of blade erodynamic
characteristics. These changes do not only influence wind turbine efficiency but also cause more noise emissions. Future rotors are expected to rotate even faster, which deteriorates the problem: At higher velocity raindrops strike harder against coatings causing even greater damage.

Climatized Rain Erosion Test Stand
The test stand will deliver data to evaluate the resistance of rotor blade coatings to rain erosion. For this purpose, the test stand is equipped with rotating arms. Specimens will be tested with blade tip speeds of up to 550 km/h. The test conditions are variable - rotational speeds and climatic conditions can be adjusted individually according to the respective real rotor blade operating conditions. Weather and operational data records provide the necessary basis. Tests can be configured due to client´s requirements.

Improved Coatings - more Efficiency
Assessing damage mechanisms serves as a basis for the optimization of coating materials such as foils and paint and for the introduction of further measures such as, for example, changes in wind turbine operational management or adjustments to maintenance intervals.