NETHERLANDS: Dutch invention could cut down aircraft fuel emissions - good news for the environment

Reducing the fuel consumption of the world's aeroplanes is a central issue to both the airline industry and environmentalists: as the industry constantly tries to push down the cost of flying environmentalists want to see a substantial reduction in carbon dioxide (CO2) emissions. Within the European Union aircraft are responsible for 3 percent of 27-nation bloc's carbon emissions. The European Commissioner for the Environment Stavros Dimas says that a boom in flying has led to a "rapid rise in greenhouse gas emissions". Environmental groups have called on the EU to impose direct emission charges on airlines, a measure it has rejected. However it is looking into ways of taxing aviation fuel, something which is currently protected by legislation. Dutch inventor Geert Roebroeks' new invention could go some way towards satisfying both parties: he has created a new material which would make aircraft wings lighter and in so doing reduce fuel consumption. According to a press release issued by the Technical University of Delft (TU Delft) the unusual qualities of Roebroek's new CentrAl - Central Reinforced Aluminium - "can make a significant contribution to the development of truly energy-efficient, 'green' aircraft. Lower fuel consumption and lower maintenance costs could lead to worldwide savings( for the aircraft industry) as high as 75 billion euros". Roebroek of AGM Advanced Structures is the man who invented the aluminium-based material called "GLARE" which is now used in the building of the Airbus 380's cabin skin. But it was too thin for the manufacture of the plane's wings and so he started looking for a suitable alternative which would be both lighter and resistant to metal fatigue. CentraAl is the result of his research at TU Delft is CentrAl. Again the university's press information explains that fatigue is a phenomenon that affects materials after long-term exposure to cyclic loading. As a result of varying loads, fractures eventually occur. The new, high-quality CentrAl aluminium constructions are stronger than the carbon fibre reinforced plastic (CFRP) constructions that have recently been used in aircraft wings such as the Boeing 787. Roebroek says CentrAl reduces the wing's weight by 20 per cent compared to CFRP constructions. That means the plane needs less fuel to fly as well as cheaper manufacturing and maintenance costs. The Dutch inventor needs two more years before it can be applied. "This combination of material is very new, the Glare part in it is already flying on actual aircraft for some years, but the combination like this is brand new. It was developed starting in 2005 and by the end of 2005 we had the first material which looked very similar to this one. But, from that moment on we still did additional developments of actual fibre layers and thicknesses and it will still develop further from now on, so we hope within, let's say. one or two years to have the final stage of this material," Roebroek says. The way that CentrAl works is by sandwiching a layer of fibre metal laminate (FML) between one or more thick layers of high-quality aluminium. This creates a very robust material which is exceptionally strong as well as being very resistant to metal fatigue. Roebroek says that, as with aluminium constructs, repairs are simple and fast which is not the case with CFRP constructions. "With this material there is an additional candidate for the lower wing skin, alongside with the existing metal and the new carbon composites. This means that, if you would use it, you would save weight, let's say comparing to the existing aluminium and therefore aircraft are lighter, aircraft use less fuel, aircraft can fly over longer distance," Roebroek says. CentrAl was born out of a collaboration between the company GTM Advanced Structures, founded in The Hague in 2004 and specialising in new aircraft materials and constructions, the American aluminium company Alcoa, and the Faculty of Aerospace Engineering of TU Delft. It was unveiled at a conference in Delft on Damage Tolerance of Aircraft Structures last September which GTM and Alcoa used to introduce to international experts in the field of metal fatigue and damage sensitivity of aircraft constructions. "This means that, if you would use it, you would save weight, let's say comparing to the existing aluminium and therefore aircraft are lighter, aircraft use less fuel, aircraft can fly over longer distance," Roebroeks says. The European Parliament this month (October 2) voted to move up the proposed date by which all airlines flying to, from and within the European Union should be included in the bloc's emissions trading system by one year to 2010. Roebroek thinks production of CentrAl could start in 2009. The scheme sets limits on the amount of CO2 -- the main greenhouse gas -- that big industries can emit and allows companies to buy or sell emissions permits depending on whether they exceed or undercut their limits. The committee voted in favour of a proposal that 50 percent of the CO2 credits that airlines would need to participate in the scheme be sold or auctioned to them rather than given away. Airlines oppose such a high level of auctioning, while environmentalists prefer more. The Commission's proposal foresees a much lower amount of permits being distributed to airlines in that way. The challenge is on and pressure is mounting on airlines to reduce their carbon footprint sooner rather than later. Roebroek's invention may be a small step but it is going in the right direction and the airline and aircraft industry may not be able to afford to ignore it.

ITN Source | October 15, 2007

Tags:. .reduction. .layers. .exposure. .composites. .sandwiching