LABELO – Laser structured anti-ice coating for aircraft surfaces

 

funded by: FFG, opens an external URL in a new window

project number: 43317863

project end: September 2025

 

Icing of aerodynamic elements on aircraft can have a negative effect on flight and, depending on the accumulation of ice, can even lead to stalling. Anti-icing and de-icing strategies are therefore essential when operating aircraft. Various active systems are used to de-ice wing sections (usually the leading edge). Pneumatically supplied, flexible rubber mats (boots) change the surface when ice is detected by introducing air and thereby blowing it off. Thermal systems heat certain zones to keep them free of ice or to melt accumulated ice. They are either electrically heated or supplied with bleed air from the engine. With chemical systems, an anti-icing fluid is pumped onto the wing surface, creating a thin film that prevents ice formation. Each of these systems has disadvantages: a lot of energy is required for thermal de-icing, pneumatic systems are very maintenance-intensive and have a negative effect on aerodynamics, and chemical de-icing leads to additional weight loading and a limited range in critical conditions.

 

In der Bildmitte liegt eine (wenige Millimeter dicke) Metallplatte. Die Metallplatte wirkt am Rand einheitlich metallisch matt (etwa 80% der Fläche) und in der Mitte deutlich heller mit längs verlaufenden Streifen und stärkerer Lichtreflexion. Unmittelbar über dieser, im rechten Winkel, hängt eine zylindrische Nadel herab. Es findet keine Berührung statt. Am Nadelende(wenige Millimeter über der Platte) hängt noch ein durchsichtiger, sphärischer Flüssigkeitstropfen herab. Die Metallplatte liegt auf schwarzer Unterlage mit weißen Karomuster.

© Matthias Heisler

Contact angle measurement of a nanostructured sample

In order to assess the performance of the anti-ice coatings developed in LABELO, experimental icing tests are carried out with various test specimens. For this purpose, the wetting and de-icing behavior is measured, and investigations are carried out in an aerodynamic environment in the icing wind tunnel. Furthermore, selected ice- phobic surfaces are applied to rotors and subjected to highly dynamic icing conditions on a rotor test bench. The focus here is on ice shedding, i.e. the detachment of accumulated ice, as a function of the resulting g-forces. The difference in required g-forces between reference and sample is a direct measure of the efficiency of the new system. In addition to the experimental work, ice formation and adhesion are also considered theoretically. The numerical simulation of wetting and icing processes is an important part of this project. Existing simulation models are to be improved and expanded in order to be able to make better predictions about icing processes and behavior in the future. The results of the experimental tests are used to validate the simulations.