Review of acoustic liner models with flow
Résumé
Acoustic linings are routinely used in the intakes and bypass ducts of civilian aeroengines in order to reduce noise. They are often modelled as a complex impedance, $Z(\omega) = p/v$, where a pressure $p\exp\{{\rm i}\omega t\}$ gives rise to a fluid velocity normal to the liner of $v\exp\{{\rm i}\omega t\}$. This presentation will give a review of acoustic lining models, including both physical (empirically derived) models for $Z(\omega)$, and mathematical models for the boundary condition to be applied at an acoustic lining. The application of the boundary condition is complicated by the presence of a mean flow over the lining; a situation typically encountered in aeroengines. The controversy over the stability of flow over an acoustic lining will be explained, together with recent attempts to resolve this controversy, both experimentally and mathematically.
Domaines
Acoustique [physics.class-ph]Origine | Fichiers éditeurs autorisés sur une archive ouverte |
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