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Description
The interaction between acoustic waves and turbulent grazing flow over liners strongly affects their aeroacoustic performance. This study experimentally investigates the influence of source location on near-orifice flow dynamics and liner response using Laser Doppler Velocimetry (LDV) in ONERA’s Aero-Thermo-Acoustic facility, providing high-resolution velocity measurements. The analysis focuses on the region close to an orifice, where coupling between the turbulent boundary layer and the acoustic field is strongest. Mean and root-mean-square (RMS) velocities are examined together with the acoustic velocity field, extracted from LDV data by cross-correlation with a reference source signal, allowing the determination of both amplitude and phase. The results show a marked sensitivity of the near-wall fluctuating velocity and coherent velocity distribution to source position. These findings provide new insight into liner–flow–acoustic interactions and highlight the critical role of source location under realistic grazing flow conditions.