In order to substantially decrease the noise and environmental impact of aviation, in parallel to advances in propulsion technologies, the quest for a full understanding of the noise source mechanism (for example associated with the laminar-to-turbulent flow transition, fully turbulent flow regime, high lift devices, landing gears, etc) remains open especially for future aircraft configurations adopting breakthrough technologies. Hence, proposals should address at least two of the following areas:
- Compatibility between thrust effectors (fan/propeller electrically or mechanically driven) and higher degree of integration into disruptive airframe configurations (e.g. Boundary Layer Ingestion, wing distributed propulsion).
- A better understanding of the noise source mechanisms for high bypass ratio turbofan engines for evolutionary and disruptive aircraft architectures such as distributed propulsion or closer engine/wing integration.
- A better understanding of the noise source mechanism associated with the laminar-to-turbulent flow transition and fully turbulent flow regime.
- A better understanding of the leading/trailing edge noise generated at landing by high-lift devices and undercarriage, including new acoustic treatments on nacelle and aircraft structures.
- Innovative propulsion technologies to address the critical topics related to the further increase of overall pressure ratio and gas temperatures needed to drive efficiency such as: reducing fuel consumption by improving thermal and propulsion efficiency, reducing Particle Number (PN), CO2 and NOx emissions by advanced combustion technologies, reducing engine weight and dimensions gaining substantial benefits on aircraft level.
The proposals are expected also to develop multi-physics modelling, numerical simulation and optimisation exploiting High Performing Computing capabilities, innovative flow control technologies, and experimental methodologies.
Proposals should ideally address TRLs ranging from 1 to 4. The Commission considers that proposals requesting a contribution from the EU between EUR 3 and 5 million would allow this specific challenge to be addressed appropriately. Nonetheless, this does not preclude submission and selection of proposals requesting other amounts.
Significant progress has been done recently in terms of environmental emission (including noise) by the development of Ultra High Pressure Ratio and Ultra High By-Pass Ratio engines. Technology assessments based on the turbofan engine configuration are indicating that there is still remarkable potential inherent in the turbofan engine configuration to be realised to further reduce gaseous and noise emissions. However, as far as noise is considered it is necessary to address the interaction between engines and aerodynamics surface and the engines interaction in aircraft architecture for a better assessment of the gain in term of noise reduction. This is necessary for the above mentioned advanced engines soon available but even more for future aircraft architecture displaying distributed propulsion or closer engine/wing integration.
Results will contribute to ultra-efficient, more silent, regional, short-haul or long-haul commercial, transport aircraft that could result in demonstration activities in 2025. According to the Flightpath 2050 goals pursued by the ACARE SRIA, CO2 emissions per passenger kilometre have to be reduced by 75%, NOx by 90% and perceived noise by 65% by 2050, all relative to the year 2000. Recent achievements assessed by the CSA FORUM-AE and extrapolated at TRL6 in 2020 result in the following figures: CO2 emissions per passenger kilometre about 38% (aircraft, + engine + ATM), NOx at engine level reduced by about 60% and perceived noise reduced by about 50%. The proposals must demonstrate that their targets are going beyond these last and are approaching the ACARE 2050 goals. Proposals must substantially explain how and why their anticipated targets are realistic.