UK multinational GKN Aerospace has obtained its patent rights for developing a new ice adhesion test device.

The device incorporates an apparatus that stimulate icing conditions and then determine in-situ ice adhesion, offering quick and economical assessment of promising ice phobic coatings and other protective technologies.

GKN Aerospace senior vice-president of engineering and technology Russ Dunn said: “Effective ice protection, including icephobic coatings, is a key focus for aerospace, as preventing ice accretion is a critical safety requirement. Efficient ice protection systems lower power consumption, improving aircraft efficiency and lowering emissions.

“To date, the most comprehensive method for measuring and understanding the icephobic nature of a surface is through icing tests using a wind tunnel. These require large, dedicated wind tunnel facilities, making them costly and impractical for regular use as a development tool, or for batch quality control in production.”

"Efficient ice protection systems lower power consumption, improving aircraft efficiency and lowering emissions."

The new device consists of a test chamber with a water ejection system and ice adhesion test apparatus.

After getting ejected, the water droplets fall through the interiors of a cooled column, thereby becoming supercooled.

They freeze on impact with the surface under analysis, situated at the base of the column.

Several parameters such as the distance from the water nozzles to the surface, the size of the water droplets, the test area and test temperature can all be adjusted to get representative environmental conditions.

When the desired ice layer is achieved, its adhesion to the surface can be tested within the chamber, with both ice accretion and the adhesion tests viewable through a port on its side.

Dunn added: “Although more extensive trials are required to fully understand how to optimise settings and analyse data, we believe this new method of testing ice accretion will speed the development of ice-phobic coatings and other ice protection technologies by reducing the cost and time involved in testing, and by enabling more testing at an earlier stage in the development cycle, the quality and focus of development programmes will also improve.

“Wind tunnel testing would then be more effectively applied in large-scale and system performance verification tests.”

Image: Testing the ice adhesion performance of a GKN Aerospace-developed icephobic coating inside the firm's new benchtop test device. Photo: courtesy of GKN.