LinerFun · Advanced Acoustic Liners Concept: An innovative Approach to Predicting Sound Propagation Using Physics-Improved Time-Domain Impedance Boundary Conditions

Aircraft engines generate significant noise during takeoff and landing, prompting the use of acoustic liners (ALs) in engine nacelles for noise reduction. However, conventional ALs are inadequate for modern Ultra-High Bypass Ratio (UHBR) engines, which require thicker liners to cope with lower fan speeds, resulting in increased drag and design trade-offs. LINERFUN tackles the challenge of designing novel ALs that provide the necessary noise attenuation with reduced size without compromising aerodynamic efficiency. This complex task demands innovative solutions and a deep understanding of AL physics. LINERFUN aims to develop a physics-improved TDIBC (piTDIBC) model using scale-resolving simulations to predict sound propagation in turbulent flows within lined ducts. The piTDIBC model addresses the limitations of existing impedance models, which often fail to capture the intricate interaction between acoustic and aerodynamic phenomena. Due to piTDIBC's efficiency, LINERFUN will drive innovation in AL studies in academia and industry, enabling the conceptualization of ALs that meet the aeroacoustic, aerodynamic, and geometric challenges of UHBR engines. The project fosters interdisciplinary collaboration between Politecnico di Torino, the University of Melbourne, and ONERA, ensuring knowledge transfer among partners. Developing a new AL prototype to address UHBR acoustic challenges could be a significant milestone for the aerospace industry, revolutionizing AL technology and offering advanced tools for designing quieter, more efficient engines. LINERFUN contributes to the broader goals of reducing environmental impact and promoting the sustainability of modern air travel.