Patent ID: 7819224

Claim:
An acoustically absorbent lining for a hot gas flow channel of an arrangement for abatement of noise generated by a turbofan drive comprising: a plurality of adjacent cavities, each of said cavities defined by side faces, a ground face, and a perforated cover plate, and four horns attached to each cover plate and extending from said cover plate into each cavity of said plurality of adjacent cavities, each of said horns defining a mouth having a mouth area and a throat having a throat area that is smaller than said mouth area, wherein all of the four horns are attached at respective mouths thereof to said perforated cover plate, wherein perforations in said cover plate are confined to discrete perforation areas of said cover plate, with unperforated areas of said cover plate disposed therebetween, said discrete perforation areas being delimited by the mouth areas of said horns, and wherein the cover plate forms a wall of the hot gas flow channel.