It’s essential to keep an airplane ice-free because a coating of ice on the aircraft’s wing can disrupt airflow and affect the lift, which is what holds the plane in the air. Unfortunately, the chemical de-icers that are applied before takeoff can be expensive, it’s not eco-friendly, and many people have experienced plane delays as they wait for their airplane to be de-iced. To remedy these issues, German scientists have developed an ice-repelling laser-based treatment for aircraft surfaces.
Some airplanes have already applied some kind of de-icer features such as integrating heat elements in crucial areas of their fuselage or setups that divert hot air from their engines to those same areas. These features make it possible to put less of the de-icing chemical while doing the same job. However, the new ice-repelling laser-based treatment is designed to minimize the need for those chemicals further. Those involved with developing the technology include the Fraunhofer Institute for Material and Beam Technology, the Dresden University of Technology, and Airbus.
The new method utilizes a variation on an existing technique called Direct Laser Interference Patterning (DLIP). How does DLIP work? It divides a single laser beam into two or more “sub-beams,’ then when those beams are focused at the same time on the surface, their light waves overlap and develop interference patterns. Those patterns are used to etch three-dimensional microscale structures onto the surface. The machine works fast, too, with up to one square meter of material treated per minute.
The scientists used the modified DLIP technique in the lab and applied 3D multi-layered microstructures to the aluminum surface of a NACA-style airfoil, acting as the airplane wing. Those microstructures, inspired by the lotus leaf, present a fragmented surface, limiting the number of adhesion points for ice.
The team then placed the internally-heated airfoil in a wind tunnel, where it was exposed to wind speeds varying from 65 to 120 meters per second, temperatures below -10 ºC (14 ºF), and various humidity levels. They found that when the airfoil wasn’t heated, any accumulated ice would fall off after a certain amount of build-up. When the model’s heating element produced 60 watts of heat, the ice that accumulated melted away within five seconds.
On the contrary, when the same amount of heat was built in a non-DLIP-treated airfoil, it took 70 seconds for the ice to melt. Now, the team plans to test the treatment in actual flight conditions, particularly on an Airbus A350 aircraft.
According to the FAA (Federal Aviation Administration), the parts of the airplane that might require de-icing and anti-icing are:
- Wings
- Propellers
- Engine inlets and fan blades
- Vertical and horizontal tail surfaces
- Fuselage
- Control surfaces and gaps
- Landing gear and landing gear door
- Antennas and sensors
