European engine makers aim to remain competitive with advanced technology being developed under an EC 'green-engine' project


Engine makers across Europe are, for the first time, working in concert on a single research and development effort. Launched in March last year by the European Commission (EC), the four-year Efficient and Environmentally Friendly Aeroengine (EEFAE) project is aimed at reducing engine emissions and increasing efficiency while, at the same time, helping cut production and life-cycle costs.

For the first time this gives companies in nine countries a coherent and comprehensive advanced technology development agenda to compare with US Government-backed efforts such as IHPTET (Integrated High Performance Turbine Engine Technology) and UEET (Ultra Efficient Engine Technology).


The EEFAE is split into two main thrusts, the short- to medium-term Affordable Near Term Low Emissions (ANTLE) validation vehicle, and the longer term Component VaLidator for Environmentally-friendly Aero Engine (CLEAN) effort. ANTLE, comprising a team of eight partners led by Rolls-Royce, is aimed at developing and maturing technology for 50,000lb-110,000lb-thrust (223-490kN) engines (ie for widebody aircraft) with a target in-service date of around 2008.

Narrowbody technology

CLEAN is focused on the medium- tolong-term development of technology applicable to narrow-body aircraft engines, and is led by Snecma and MTU. It also includes ANTLE team members Eldim, FiatAvio, Techspace Aero and Volvo, as well as ESIL of Ireland and the French CEPR Institute. These latter members are studying an inter-cooled recuperated aeroengine (IRA) concept which builds on the principles developed for heat exchangers.

The EC says the "goal is to validate in CLEAN some core technologies for a future IRA concept." CLEAN will also test an improved, high-efficiency high-pressure (HP) compressor with active surge control, a low-emissions axially staged combustor and a high-temperature HP turbine from Snecma. FiatAvio will have a key role in developing the combustor module, while MTU will provide a two/three-stage low pressure (LP) turbine and a new structural inter-turbine frame.

Volvo is developing a low-cost turbine exhaust rear frame, and MTU will work with the IRA group to locate a new heat exchanger segment in the LP turbine exhaust stream. The CLEAN team plans to cut carbon dioxide (CO2) emissions by 20%, largely due to the IRA heat exchanger device, and reduce nitrous oxide (NOx) emissions by a staggering 80%. The EC cautions that the CLEAN timescale is longer, and "...because of the considerable technical challenges to be faced, flight testing of a future IRA engine is unlikely to take place until 2015, while commercial service will not commence before 2020." The initial CLEAN configuration is, however, due to begin rig tests at the CEPR site in Saclay in mid-2003.

ANTLE targets

Unlike US programmes which tend to be benchmarked against specific engines such as the General Electric GE90, the targets for ANTLE are judged against "existing 1990s technology" engines used on the Airbus family. These targets include a 12% cut in fuel consumption and CO2 emissions, a 60% cut in NOx (relative to ICAO 1996 standards), as well as significant cost and life cycle reductions. Reliability improvement is targeted at 60%, cost of ownership reduction at 20% and life-cycle cost reduction at 30%. ANTLE also hopes to demonstrate up to 50% reduction in time-to-market engine development.

Rolls-Royce's ANTLE partners include the UK company's German-based R-R Deutschland division, ITP of Spain, FiatAvio of Italy, Volvo of Sweden, Belgium's Techspace Aero, Hispano-Suiza of France and TRW (formerly Lucas) of the UK. Supporting research and development is being provided by the universities of Florence in Italy and Lulea in Sweden.

Although the EEFAE/ANTLE effort is currently only contracted for four years, Rolls-Royce says it has already "declared our intention" to perform additional tests into 2004 and beyond. These will be aimed at "more extensive demonstration of advanced technologies and will enable better integration" leading to maximum benefit to be obtained from follow-on EC funded programmes such as the Snecma-led SILENCE noise reduction project.

EU initiatives

"As well as EU initiatives, we are also drawing on national projects to pull it all together. EEFAE is the focal point for an awful lot of activities all over Europe," says Rolls-Royce ANTLE chief engineer Steve Morgan. The partners held an initial preliminary design review meeting in December at which the baseline concept definition was agreed on. Adds Morgan: "We are now at the stage of freezing the design of the experimental vehicle itself. We will have the equivalent of what would be the first critical design review in the next few weeks."

The design reviews are being held in parallel with an extensive series of on-going rig tests on elements of the combustor and compressor. The compressor rig is due to run in the third quarter of 2001, with a similar rig test of the core turbine following shortly after. A LP turbine rig test and full annular combustor rig evaluation are to begin in the third quarter of 2002.

Pending successful rig tests throughout the rest of this year and next, the first hardware elements of the full-up ANTLE engine test are expected to come together in early 2003. Rolls-Royce plans to use the 50,000lb-thrust Trent 500 as the basis for the testbed engine, which will be delivered to the Spanish INTA test site near Madrid in September for tests running into the fourth quarter of 2003. Testing at INTA is expected to comprise at least 75h focused on starting, general operability and emissions monitoring. Analysis of the results will be conducted through the rest of 2003 and into 2004 for final reporting to the EC in March 2004.

New elements added to the engine are chiefly in the hot section. "It's all-new from the back of the IPC [intermediate pressure compressor], with everything focused on achieving the ANTLE targets," says Morgan, who adds that noise reduction technology is not the programme's aim.

Source: Flight International