FFLECS · Novel Fuel-Flexible ultra-Low Emissions Combustion systems for Sustainable aviation

Improving Local Air Quality at airports while at the same time decarbonising aviation can be achieved by switching to sustainable aviation fuels (SAFs) and hydrogen (H2), as confirmed by recent engine development programs. However, both these fuels require significant developments in the gas-turbine combustor because present technologies not only to further reduce NOx and PM emissions as expected by long-term standards and objectives but also are not normally suitable for 100% direct combustion of hydrogen. In this project, revolutionary combustor architectures will be studied, extending the preliminary results of previous Clean Sky 2 ""Innovative NOx Reduction Technologies"" projects in terms of scientific scope and TRL. In particular, this project will advance (i) the Lean Azimuthal Flame (LEAFinnox), a novel combustion system based on Flameless Oxidation, (ii) the Compact Helically Arranged combustoR (CHAIRlift), a new system which uses interacting lean lifted flames, and (iii) plasma and electric manipulation of the spray and of the flame stabilisation mechanism. The fuel flexibility offered by these novel concepts is key to allow for SAF and H2 operations. This unique feature will be exploited to give novel dual-fuel LTO cycle strategies and ultra-low NOx, ultra-low soot single or dual-fuel use. Experiments on available dedicated rigs and numerical work will be performed to provide knowledge at the fundamental and practical level that will allow TRL3 and higher developments at the end of the project. The project will include new CFD, low-order, and AI models, and novel stabilisation techniques ripe for commercial exploitation.""