Overview
Increasing the overall pressure ratio will result in reduction of CO2. But this will also lead to increase of NOx.
The main objective of the LEMCOTEC project will be the improvement of core-engine thermal efficiency by increasing the overall pressure ratio ("OPR") to up to 70 leading to a further reduction of CO2. Since NOx increases with OPR, combustion technologies have to be further developed, at the same time, to at least compensate for this effect. The project will attain and exceed the ACARE targets for 2020 and will be going beyond the CO2 reductions to be achieved by on-going FP6 and FP7 programmes including Clean Sky:
- CO2: minus 50% per passenger kilometre by 2020, with an engine contribution of 15 to 20%;
- NOx: minus 80% by 2020 and;
- Reduce other emissions: soot, CO, UHC, SOx, particulates;
The major technical subjects to be addressed by the project are:
- Innovative compressor for the ultra-high pressure ratio cycle (OPR 70) and associated thermal management technologies;
- Combustor-turbine interaction for higher turbine efficiency & ultra-high OPR cycles;
- Low NOx combustion systems for ultra-high OPR cycles;
- Advanced structures to enable high OPR engines & integration with heat exchangers;
- Reduced cooling requirements and stiffer structures for turbo-machinery efficiency;
- HP/IP compressor stability control.
The first four subjects will enable the engine industry to extend their design space beyond the overall pressure ratio of 50, which is the practical limit in the latest engines.
Rig testing is required to validate the respective designs as well as the simulation tools to be developed. The last two subjects have already been researched on the last two subjects by NEWAC. The technology developed in NEWAC (mainly component and/or breadboard validation in a laboratory environment) will be driven further in LEMCOTEC for UHPR core engines. These technologies will be validated at a higher readiness level of up to TRL 5 (component and/or breadboard validation in a relevant environment) for ultra-high OPR core-engines.
Funding
Results
Aero engines with lower emissions across the board
The EU is committed to the development of more efficient aero engines for green and sustainable air transport. Novel core-engine technologies promise to significantly and simultaneously reduce major categories of emissions.
As global air traffic continues to grow, so do associated emissions and environmental impact. The aviation industry is facing a major challenge to satisfy customer demand in an eco-friendly and sustainable way.
In its Vision 2020, the Advisory Council for Aviation Research and Innovation in Europe (ACARE) has set ambitious targets for reduction of carbon dioxide (CO2), nitrogen oxides (NOx) and other emissions. EU-funded scientists working on the http://www.lemcotec.eu/ (LEMCOTEC) (Low emissions core-engine technologies) project plan to exceed these targets.
The path to success lies in increasing the overall pressure ratio (OPR) of the engine up to 70 and higher for substantial improvement in core-engine thermal efficiency and reduced CO2 emissions. However, increasing the OPR increases NOx emissions, so other technologies must be developed to compensate for this effect.
Research is focused on four key technical innovations in four major areas. These are the compressor itself, combustor-turbine interaction, lean combustion systems for low NOx emissions, and advanced ultra-high OPR engine structures and associated thermal management technologies. Design work is being extensively supported by fluid dynamics modelling.
Lean combustion technologies exploit a lean (low) fuel-to-air ratio, enabling significant reductions in emissions. They rely on advanced fuel injection and fuel control technologies.
Scientists analysed advanced fuel injection system concepts and specified the architectures for the fuel control systems. A test rig enabling exploitation of new measurement techniques at the interface between the combustor outlet and the high-pressure turbine inlet was successfully implemented, yielding excellent results. Some injection systems have also been tested, resulting in selection of certain designs for integration into the final prototypes. Finally, fuel control systems are in various stages of manufacture and will be tested in the upcoming months.
Advanced ultra-high OPR engine structures and thermal management systems, including an improved compressor case, extended temperature materials and a low-leakage liner, are in various stages of design, manufacture and testing.
LEMCOTEC technologies promise to achieve very high OPR and thus increase core-engine thermal efficiency. This will lead to the simultaneous reduction in CO2, NOx and other emissions beyond the ambitious targets of ACARE's Vision 2020 for sustainable and more eco-friendly air transport in the near future.