Engineering news
The carbon dioxide emissions of air traffic are increasing as air traffic around the world by about 5% every year. For every 100 kilometres flown by just one passenger, up to four litres of fuel can be burned. Such increases pose a significant challenge to attaining any targeted reduction in greenhouse gas emissions in the battle against climate change.
Engineers on a €68 million EU aerospace research project have been working hard on developing more efficient jet engine technology for the last five years to help reduce the effect air travel has on the environment. The latest results from the LEMCOTEC (Low Emissions Core Engine Technologies) project reduces NOx by 70% while reducing CO2 emissions by up to 28% compared to technology and standards from the year 2000.
The LEMCOTEC project, which has involved researchers from several leading aero-engine manufacturers, has developed new core-engine architecture, which researchers on the project say makes it possible to achieve “ultra-high” overall pressure ratios of up to 70:1.
For comparison the Rolls-Royce Trent 900 engine, which is used to power the Airbus A380, has a pressure ratio of 39:1.
Researchers from Germany, Italy, UK, France, Sweden, Spain, the Czech Republic, Poland, Greece, Russia and Belgium worked to improve the technology of the components and subsystems that make up a core-engine. This included the compressors, lean combustion systems, combustor-turbine interfaces and turbines. They also devised new engine structures to cope with the significantly increased pressures.
The major challenge was that although an improvement to the core-engine’s thermal efficiency enables a reduction in CO2 emissions through improved efficiencies, whenever the overall pressure ratio (OPR) is increased, NOx emissions go up if no corrective measures are taken. The project had to therefore develop new lean-burn technologies to mitigate this negative NOx effect.
The project developed a subsystem that integrates lean-burn technology with an advanced injection system. According to the latest experiments with the lean combustion subsystem, the engine is on track to meeting its 65 to 70 % NOx reduction targets.
The project has concluded that just by improving the efficiencies of an engine subsystem an aircraft’s overall emission footprint can be reduced by up to two litres of fuel per passenger per 100 kilometres travelled.
Dr. Ralf von der Bank, coordinator of the LEMCOTEC Research Programme, said: “This is a substantial improvement in efficiency earned from a focus on the core-engine, which is just one component of an aircraft and just a small part of the air travel value chain.
“It’s really just the tip of the iceberg. When combined with the efficiency improvements happening in airframes, operations and air traffic management, the goals begin to look very realistic. In the long term, specific fuel consumption of just one litre per 100 passenger kilometres has become a realistic goal.”
According to von der Bank, the research will also help to reduce the overall costs of air transportation. “More efficient engines means less fuel burned and savings that can go towards enhancing Europe’s role as technology leader and towards lowering airfares.”
“With less money being spent on air travel, European industry will be able to maintain its competitive edge, and maintain its potential for growth which, in the end, benefits the entire European economy and society.”
The EU has contributed €40 million to the project, which is due to conclude this September. Industry partners included SNECMA, MTU Aero Engines, Rolls-Royce plc, Volvo Aero, ITP, Avio, Turbomeca, the German and French national aerospace research centres, DLR and ONERA, and several leading European universities in the field.