The conventional anti-icing system on most passenger aircraft is based on hot air which is ‘bled’ from the engines and piped to the inner surface of the wing. The heat is then transferred to the outer surface by thermal conduction, which stops the ice from building. This system adds weight and maintenance requirements, and is not energy efficient, particularly on the new generation of composite aircraft.
A team of experts at Queen’s University have developed a more efficient alternative: an ultra-light weight heater, based on ‘webs’ made from carbon nanotubes (CNT), which can also be used for de-icing.
Professor Brian Falzon, School of Mechanical and Aerospace Engineering, led the Queen’s team. He explains: “This research is funded by the Engineering and Physical Sciences Research Council (EPSRC) and forms part of a larger research programme aimed at developing the aircraft structures of tomorrow. We started by creating a ‘CNT web’, where individual CNTs are aligned in the draw direction, and horizontally stacking 10-40 layers of the webs, at different orientations, to achieve the desired heating characteristics.
“Each layer of CNT web can be as thin as 1/2000 the thickness of a human hair and the weight of a web large enough to cover a football field would be less than 30 sheets of A4 photocopy paper.
“These CNT webs were cured within a thin glass fibre laminate to provide structural support, and connected to a power supply.”
During testing, the team discovered that the newly developed CNT heaters achieved rapid heating, demonstrating that the CNT heaters could quickly de-ice aircraft and provide effective ice prevention in flight.
Compared with state-of-the-art heating systems currently used on aircraft, the CNT heater created at Queen’s university is lighter, quicker, more energy efficient and provides more uniform heating. It is also more flexible in terms of fitting the shape of any surface or power requirement.
The team is developing further research on the system and it is hoped that it will be in use within a few years.
