Waggling wings cut emissions by 20 percent
15 Jul 2009 by Evoluted New Media
In a surprise discovery, UK engineers have found that aircraft wings which redirect air to waggle sideways could cut airline fuel bills by 20%.
In a surprise discovery, UK engineers have found that aircraft wings which redirect air to waggle sideways could cut airline fuel bills by 20%.
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| Waggling wings could help reduce the environmental cost of flying |
The jets work by the Helmholtz resonance principle – when air is forced into a cavity the pressure increases, which forces air out and sucks it back in again, causing an oscillation – the same phenomenon that happen when blowing over a bottle.
Dr Duncan Lockerby, from the University of Warwick, who is leading the project, said: “This has come as a bit of a surprise to all of us in the aerodynamics community. It was discovered, essentially, by waggling a piece of wing from side to side in a wind tunnel.
“The truth is we’re not exactly sure why this technology reduces drag but with the pressure of climate change we can’t afford to wait around to find out. So we are pushing ahead with prototypes and have a separate three year project to look more carefully at the physics behind it.”
The UK aviation industry has announced targets to reduce emissions per passenger km by 50% by 2020. Part of these savings will be made from lighter aircraft plus improvements in engines and fuel efficiencies but drag friction is also a major factor in fuel consumption during flights. Engineers have known for some time that tiny ridges known as ‘riblets’ - like those found on sharks bodies - can reduce skin-friction drag, (a major portion of mid-flight drag), by around 5%. But the new micro-jet system being developed by Dr Lockerby and his colleagues could reduce skin friction drag by up to 40%.
Simon Crook, senior manager for aerospace & defence at Engineering and Physical Sciences Research Council, said: “This could help drastically reduce the environmental cost of flying. Research like this highlights the way UK scientists and engineers continue to make significant contributions to our lives.”
