C3.5 - Numerical investigations of synthetic fuel flames in aviation conditions

Climate change imposes a drastic reduction in greenhouse gas emissions and urges for a rapid transition towards carbon-neutral technologies with the final aim to minimize pollution and preserve life on the planet. Aviation propulsion, as a hard-to-decarbonize sector, requires a multifaceted approach to address diverse aircraft missions. This involves various carbon-neutral and carbon-free energy carriers such as hydrogen, sustainable aviation fuels (SAFs), and innovative propulsion concepts like electric systems. While electric propulsion will be a game-changer technology for short-range flights, jet fuels remain essential for medium- to long-range aircraft.

Synthetic fuels, particularly SAFs, are currently emerging as promising replacements for fossil jet fuels. These fuels can be produced from sustainable feedstocks or synthesized with renewable energy. SAFs have the advantage of being drop-in fuels, minimizing the need for engine and distribution system modifications. However, despite their carbon emission mitigation capabilities, SAF combustion may still generate soot particles, posing health and environmental challenges. To address this issue, different fuels have been explored as alternative aviation fuels, to potentially reduce soot emissions. While progress has been made, a comprehensive understanding of the relationship between the fuel molecular structure and particle formation remains incomplete and further research is required for a comprehensive characterization of SAFs.

This project aims to develop and apply high-performance computing numerical models to gain a comprehensive understanding of the emission characteristics of sustainable aviation fuels, particularly on non-volatile soot particle formation. A tight collaboration in SE²A with ICA C3.3 will provide detailed kinetic mechanisms to perform the simulations and experimental data for model validation. A series of numerical simulations will be carried out, both at atmospheric and real engine conditions. These will allow to unravel the mechanism of soot formation in the combustion of SAFs, aiming to link the molecular structure of the fuel with the soot formation characteristics and the physicochemical properties of the formed particles. This project will be complementary to ICA C3.3, leading to comprehensive numerical and experimental investigations of SAF under a wide range of operating conditions.