Conveners
A07.03 Noise reduction technologies for aeroacoustics (active and passive): S043
- Anita Schulz (HTW Berlin)
- Yves Aurégan (Labo Acoutique de l'Université du Mans)
- Francesco Avallone (Politecnico di Torino)
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Yves Aurégan (Labo Acoutique de l'Université du Mans)09/09/2026, 14:20A07 Flow Acoustics
Deep axisymmetric cavities integrated into a chamber significantly influence acoustic wave propagation, notably by reducing the effective sound velocity. In our experimental configuration, the effective sound velocity is approximately one quarter of the sound velocity in air (c_e≈c_0/4). This substantial reduction suggests the possibility of introducing a mean flow exceeding c_e to investigate...
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Anita Schulz (HTW Berlin)09/09/2026, 14:40A07 Flow Acoustics
The extraction of complex axial wavenumbers is a key intermediate step in modal sound-field decomposition and liner impedance eduction. This paper presents a systematic benchmark comparison of the Kumaresan--Tufts (KT) and Hankel total least squares (HTLS) methods for controlled two-dimensional synthetic test cases in lined ducts. The analysis covers single-mode benchmarks for varying SNR,...
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Aymane Chaabaoui (LAUM - Université du Mans)09/09/2026, 15:00A07 Flow Acoustics
Sound scattering induced by a duct wall impedancediscontinuity located in proximity to a source is investi-gated. It is illustrated that, when a liner is positionedin a source’s near field, evanescent modes can have asignificant impact on the transmitted power, especiallyclose to their cut-off frequency. A parametric study isconducted to highlight how evanescent modes locatedclose to the liner...
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Alessandro Bassetti (Hamburg University of Technology)09/09/2026, 15:20A07 Flow Acoustics
The presence of streamwise vorticity in high speed gaseous jets can be considered beneficial in reducing jet noise. The inner walls of nacelles for turbo-fan propulsion systems are acoustically treated, in order to reduce the amplitude of turbomachinery and combustor noise that propagates through the duct. The German Aerospace Center (DLR) proposed a patent for a bias-flow liner device, called...
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Ludovic Ambrosiani (Politecnico di Torino)09/09/2026, 15:40A07 Flow Acoustics
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...
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Joanna Maria Kopania (Lodz Univerity of Technology)09/09/2026, 16:00A07 Flow Acoustics
The study demonstrated that the acoustic performance of ceiling swirl diffusers with adjustable blades is strongly influenced by both blade geometry and flow configuration. The results showed that some types of commercial profiles significantly increase noise levels, especially under unfavourable conditions of flow. The best performance was achieved by the profile with aerodynamic shape, which...
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