Aircraft noise is a pressing concern affecting communities near airports, with engine-generated noise, particularly from Ultra High Bypass Ratio (UHBR) engines, standing out as a major culprit. By the date the most widely used solutions are acoustic liners.
Geometry of Single degree of freedom acoustic liner.
Traditional acoustic liners, typically composed of honeycomb structures a perforated facesheet and a solid backplat, are known as Single degree of freedom. They are usually installed in the intake of engines.
Schematic representation of aircraft’s engine with acoustic liners.
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Despite extensive research elucidating the physics governing acoustic liners in idealized scenarios, understanding their behavior under real-world conditions—where they are subjected to both acoustic waves and turbulent airflow—remains a challenge. Our study aims to bridge this gap by exploring their behavior amidst high Mach numbers and Sound Pressure Levels (SPL).
Our investigation employs advanced numerical simulations, revealing detailed insights into flow dynamics within liners. By leveraging the Lattice-Boltzmann Very-Large-Eddy-Simulation (LB/VLES) approach, we unravel how flow characteristics influence liner impedance, crucial for refining noise reduction strategies.
Flow inside the cavity visualized through iso-surfaces of the Lambda2 Scalar, overlaid with a pressure scalar scene.
Stay tuned as we delve into the complexities of flow behavior within the cavity of acoustic liners in our forthcoming paper!