A hybrid mode-scattering/sound-absorbing segmented liner system and method in which an initial sound field within a duct is steered or scattered into higher-order modes in a first mode-scattering segment such that it is more readily and effectively absorbed in a second sound-absorbing segment. The mode-scattering segment is preferably a series of active control components positioned along the annulus of the duct, each of which includes a controller and a resonator into which a piezoelectric transducer generates the steering noise. The sound-absorbing segment is positioned acoustically downstream of the mode-scattering segment, and preferably comprises a honeycomb-backed passive acoustic liner. The invention is particularly adapted for use in turbofan engines, both in the inlet and exhaust.
Hybrid mode-scattering/sound-absorbing segmented liner system and method
09.11.1999
Sonstige
Keine Angabe
Englisch
Segmented Liner to Control Mode Scattering
AIAA | 2013
|Reduction of Aeroengine Tonal Noise using Scattering from a Multi-Segmented Liner
British Library Conference Proceedings | 2008
|Europäisches Patentamt | 2018
|