THE EUROPEAN – SECURITY AND DEFENCE UNION
Towards a new generation of aeroengines − less consumption, less Co2 and less noise
Technology for future aero engines by Dr. Rainer Martens, Chief Operating Officer, MTU Aero Engines, Munich Quieter, thriftier and cleaner, that’s what tomorrow’s engines will need to be. MTU Aero Engines has for years been working on new technologies to further improve the environmental compatibility of future engines. The effort is worth the trouble: industry experts see good growth opportunities for aviation. By 2020, they expect air traffic to double. Closely cooperating with the major players in the business, Germany’s leading engine manufacturer develops novel propulsion systems and technologies in all thrust and power categories and is involved in essential national and international research projects.
The future belongs to the geared turbofan (GTF) engine Pratt & Whitney and MTU Aero Engines are collaborating on the PurePower PW1000G engine to develop a game-changing propulsion concept. The new technology holds the promise of reducing fuel consumption and CO2 emissions by 15 percent each, and of cutting present perceived noise levels in half. The concept is catching on with airframers: Airbus is offering the geared turbofan engine for its re-engined A320neo. This could be the application for which the largest quantity of geared turbofans will be required; for the European aircraft manufacturer estimates that the market will need some 4,000 of this type of aircraft, taken over its entire life. Bombardier has also selected the GTF as the exclusive engine to power its new CSeries; Mitsubishi will equip its MRJ with this new type of propulsion system, and Irkut has chosen it for its MS-21. What sets the new GTF propulsion system apart is that it features a reduction gearbox between the fan and low-pressure turbine. With today’s engines, the two are seated on a common shaft, and the turbine drives the fan. Uncoupling them allows the fan with its large diameter to rotate more slowly and the turbine to rotate much faster. This lets the individual components achieve their respective optimum speed, greatly boosting the geared turbofan’s efficiency. The result is a significant reduction in fuel consumption, emissions of carbon dioxide and noise; moreover, the propulsion system is much lighter than a conventional engine as it has fewer stages, and hence a lower parts count. MTU contributes the high-speed low-pressure turbine to the GTF, one of its key components. Germany’s leading engine manufacturer is the sole manufacturer in the world capable of offering this technology. Moreover, Pratt & Whitney and MTU have collaborated to design a new high-pressure compressor. The new transonic compressor will achieve a compression
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Dr. Rainer Martens was born 1961, He became Chief Operating Officer of MTU Aero Engines in April 2006. He is a member of the MTU Board of Management with overall responsibility for engineering and production. Dr. Martens studied Mechanical Engineering at Hannover University in Germany and the University of Birmingham to the UK. He holds a doctorate in mechanical engineering. Before his current position he was plant and site manager at the Airbus plant in Bremen, after spending five years as the Head of MTU’s manufacturing center for turbine blades, Dr. Martens was previously also Managing Director of CIM-Fabrik Hannover GmbH in Hannover.
ratio of 17:1 with no more than eight stages, and will appreciably enhance efficiency. That’s enough to beat most commercial models by a wide margin. MTU is responsible for the forward four stages and Pratt & Whitney for stages five to eight. The innovative compressor is a 100-percent blisk construction. Blisks (blade integrated disks) are a high-tech rotor design in which the disk and blades are produced as a single piece, eliminating the need for blade roots and disk slots. This increases strength and lowers weight.
Clear Air Engine (Claire) In partnership with Bauhaus Luftfahrt, MTU has developed an ambitious program to reduce the carbon dioxide emissions of aircraft engines. Under the Clean Air Engine (Claire) technology project, a CO2 reduction of up to 30 percent is scheduled by 2035. With the initiative, the ACARE-targets will be clearly exceeded, and noise levels at the same time drastically reduced. The program is bases on the geared turbofan engine and has three stages. Plans are, in the first stage (by 2012), to lower CO2 emissions by about 15 percent and cut the perceived noise levels in half, using technologies that have been matured for production by that time. In the second step, the CO2 emission reduction will be raised to at least 20 percent by 2025. The key to success is even more efficient thrust generation − for instance by the further development of the GTF or through the use of a shrouded, counter-rotating fan, the concept for which had been developed by MTU already back in the 1980s. By 2035, MTU ultimately expects to achieve the full target of a 30 percent reduction when in the third and last stage, utilization of the energy in the core engine will be further optimized, e.g. by the use of a heat exchanger.
