In the general effort to make air traffic greener, most part of the aviation research activities has been focused toward CO2 and NOx emissions reduction while preserving the engine’s operability and keeping under control CO emissions at part power of the engine.
In Europe, the ACARE (Advisory Council for Aeronautic Research in Europe) flightpath 2050 ambitious goals about CO2, NOx and perceived noise emissions are a major source of motivation for the realization of innovative low emissions combustor able to meet these goals.
However, ACARE provided no quantified objective for the reduction of ultrafine soot particles, also emitted by aircraft engines. These particles, conventionally named Particulate Matter (PM), are known to pose serious health risks and environmental threats and could have a strong impact on air quality around airports. In addition, inside the engine combustor, soot particles may have a direct influence on flame luminosity and radiation toward the combustor walls, and impact the engine’s performances.
Despite the lack of knowledge toward soot formation processes and characterization in terms of mass and size, engine manufacturers have now to deal with both gas and particles emissions. Furthermore, heat transfer understanding, that is also influenced by soot radiation, is an important matter for the improvement of the combustor’s durability, as the key point when dealing with low-emissions combustor architectures is to adjust the air flow split between the injection system and the combustor’s walls.
The SOPRANO initiative consequently aims at providing new elements of knowledge, analysis and improved design tools, opening the way to alternative designs of combustion systems for future aircrafts capable of simultaneously reducing gaseous pollutants and particles, and improve the liner lifetime.
Therefore, the SOPRANO project will deliver more accurate experimental and numerical methodologies for predicting the soot emissions in academic or semi-technical combustion systems.
This will contribute to enhance the comprehension of soot particles formation and their impact on heat transfer through radiation.
In parallel, the durability of cooling liner materials, related to the walls air flow rate, will be addressed by heat transfer measurements and predictions. Finally, the expected contribution of SOPRANO is to apply these developments in order to determine the main promising concepts, in the framework of current low-NOx technologies, able to control the emitted soot particles in terms of mass and size over a large range of operating conditions without compromising combustor’s liner durability and performance toward NOx emissions.