Aircraft

Engine may power next generation of narrowbody aircraft

Rolls-Royce has revealed it is examining an "open rotor" concept as one of several potential engine designs that could power Airbus and Boeing's next-generation narrow­body airliners.

Colin Smith, R-R director of engineering and technology, says the open rotor concept would be developed under the €1.6 billion ($2.09 billion) European Union Clean Sky joint technology initiative (JTI), which is expected to be officially launched within weeks.

Derby-based R-R was one of nine manufacturers that last October signed a memorandum of understanding to join Europe's largest ever public-private aeronautics research project to lessen the impact of aviation on the environment, part of the EU's €50.5 billion Seventh Framework research programme, which ends in 2013.

Smith describes open rotor technology as a "game changer" offering up to 15% more fuel efficiency than a conventional two- or three- shaft turbine and a significant operating cost reduction.

Open-rotor technology represents one of R-R's four emerging concepts for aircraft in the 130- to 180-seat category, with potential higher efficiency gains driving acquisition and maintenance costs.

The engine manufacturer is also proposing a two-shaft lower-cost design featuring Engine 3E-based architecture with booster configuration capability. Engine 3E (environment, efficiency, economy) is a German government-sponsored research programme aimed at reducing noise levels by 10%, carbon dioxide emissions by 20% and nitrogen oxide emissions by 85% by 2010.

A novel engine core with a low part-count is also under consideration, as is a three-shaft Trent-based engine architecture that could operate at cooler temperatures and offer a low specific fuel consumption.

"Open-rotor engines offer 15% more fuel efficiency, but they also demand that huge changes are made to the airframe configuration," says Smith. The lower speed at which open rotor-powered aircraft fly would, he says, probably be offset by the average sector length operated by a narrowbody.

A series of demonstration power­plants for different aircraft types will be developed and tested on the ground or in flight by the beginning of the next decade within the seven-year JTI. Snecma and MTU Aero Engines are also likely to be JTI platform leaders, proposing advanced engine technology demonstrators.