The Green Engine will be on the lips of engine makers at Le Bourget this year and two European companies will be going out of their way to talk about their performance.
Italian manufacturer Avio, the former Fiat business, now part of Finmeccanica and the Carlyle Group, and Rolls-Royce have been speaking about their achievements in R&D investment toward the new Acare environmental targets.
Under the environmental impact targets specified by Acare (Advisory Council for Aeronautics Research in Europe), the "green" aircraft engine of the future, 15-20 years from now, must be characterised by a 20% reduction in fuel consumption compared with today's models.
The reduction in nitrogen oxide emissions must be improved, from the current -30% (compared with the engines constructed since the early 1990s) to -60% by 2008 and -80% by 2015.
Acoustic
As for acoustic emissions, noise levels abatement must improve by -32db in 2008 and by -45db in 2015
Ric Parker, director of research and technology at Rolls-Royce, says the British company is on track.
"We are investing some 200 million ($370 million) on technology to deliver improved environmental performance," he says. Using the Trent as an example, Parker says the engines are already ahead of the Rolls-Royce 2010 targets for fuel consumption improvements and in line to meet the Acare 2020 target.
Using 3-D aerofoils in the IP and HP compressor stages and all of the turbine stages in the Trent 900 and the Trent 1000 engines has resulted in reduced flow separation and reduced reverse flow which minimise losses.
"We have applied the same 3D CFD methods to the end walls as we did to the turbine blades - it reduces secondary flows and increases turbine efficiency," Parker says.
Meanwhile Avio has fine-tuned interheater and turbine technologies that will contribute to reduce fuel consumption by 10% and to achieve a further 30% cut in the emissions of nitrogen oxide and other irreversible pollutants in engines of new construction compared with the models currently used.
Avio devotes a major share of its investments in R&D to the new clean engine technologies, which in 2004 totalled more than 140 million ($155 million). In 2004, the financial resources invested in research accounted for 12% of Avio's turnover - an unprecedented level.
Avio's research efforts on interheaters and turbines will play a major role in reaching the targets by focusing on the redesign of these key components .
On the interheaters - essential components to reduce unburnt gases and harmful residues by improving engine efficiency - research has focused on the development of the European demonstrator Clean. The tests conducted on this device in late 2004 demonstrated that Acare targets are attainable.
Task
In the forthcoming European demonstration programme Newac, Avio's task will be to demonstrate the industrialisation of these solutions, having full responsibility for the development of the interheater for Europe's "green" engine.
In the field of turbines, of great importance in the new "green" architectures with high by-pass ratios, since 2000 Avio has initiated a number of research programmes on the new technologies.
Source: Flight Daily News
