During the winter season, ice would often build up on the wings of aircrafts and its other parts, causing delays in flights. This is a problem, especially at this time of the year where people visit their loved ones for the holidays. Currently, defrosting procedures only work by melting the ice layer by layer from the topmost and down. Aside from the lengthy amount of time, this process also consumes a lot of energy.
To address this problem, engineers from the University of Illinois Urbana-Champaign and from Kyushu University have worked together to improve the system. In a publication in Applied Physics Letters, the researchers explained how their method is more efficient and both time and energy saving.
Nenad Miljkovic, one of the researchers from UIUC, explained the problem with current defrosting systems-it is that most of the time and energy are spent on heating the parts of the aircraft rather than the ice itself. The analogy here is with simultaneous movement of glaciers. So if the ice that is directly in contact with the heated surface, then the rest of the ice will just slide off the surface. "The systems must be shut down, the working fluid is heated up, then it needs to be cooled down again," he said. "This eats up a lot of energy when you think of the yearly operational costs of running intermittent defrosting cycles."
The team proposed an improvement to this system by explaining how a pulse of very high current can be delivered to the ice-substrate interface. This can be done by introducing indium tin oxide, or ITO, onto the surface of the aircraft component.
The efficiency of the proposed system was tested when the researchers defrosted glass panel samples that were previously cooled to extremely low temperatures at -15.1 and -71 degrees Celsius-that's 4.8 and -95.8 degrees Fahrenheit, representative of the temperature extremes In Antarctica. In both tests, the glass samples were defrosted with a pulse that lasted for less than a second.
In a larger scale, of course, other factors like air flow, and size and geometry of the substrate would be considered. "In a real system, gravity would be assisted by airflow," Miljkovic explained. "At scale, it all depends on the geometry. However, the efficiency of this approach should definitely still be much better than conventional approaches." The large scale and actual application would be the focus of the next stage of the research, where they would also calculate the actual energy consumed during the process.