Aircraft engine firms fight on to improve green technology.
AIRCRAFT engine manufacturers are stepping up the drive for better environmental performance, hut are yet to meet the new levels demanded by industry.
The four main engine suppliers--Rolls-Royce, Pratt and Whitney, General Electric and CFM--have released details of a number of alternative future concepts in answer to rising fuel prices and pressure from environmentalists.
Pratt and Whitney's geared turbofan technology has been successfully trialled in the air and on the ground. The first geared turbofan, the PurePower, will enter service in 2013 to power the recently announced Bombardier C-series.
The engine uses a complex gear system to allow the engine fan to operate at a different speed to the low-pressure compressor and turbine, resulting in greater fuel efficiency, slower fan speed and less noise. The engine targets more than 12% reductions in fuel burn and C[O.sub.2] emissions and a 50% reduction in engine noise without any significant loss in performance.
The company is working with Airbus to run an A340 with the engine. Test flights are scheduled at Airbus' headquarters in Toulouse later this year.
Todd Kallman, president of Pratt and Whitney Commercial Engines said: "Testing the geared turbofan using the Airbus A340 flight test aircraft, combined with the experience of the Airbus flight test team, will provide us with valuable installation and operating data."
Both Rolls-Royce and CFM (a joint venture between Snecma and General Electric) are looking at a more radical solution and have proposed the development of an open-rotor engine. This resembles a cross between a turboprop and a turbofan and could deliver the performance and efficient fuel burn the industry is seeking.
It is hoped this concept may offer the speed and performance of a turbofan with the fuel economy of a turboprop. However, previous attempts at developing the concept have yielded a prototype that is far too noisy and would not pass today's noise regulations.
|Printer friendly Cite/link Email Feedback|
|Publication:||Professional Engineering Magazine|
|Article Type:||Brief article|
|Date:||Jul 23, 2008|
|Previous Article:||Low-power start to tidal turbine: gently does it as Strangford Lough starts feed into grid at quarter of its capacity.|
|Next Article:||Ofgem polices green tariffs for electricity.|