Patent ID: 8701822
Filing Date: 2014-04-22
Classification: F02C,F02K,F05D

Abstract:
1. A duct for guiding gas along a gas path, comprising: an outer wall; a noise-attenuating covering disposed inside the outer wall, the covering comprising an inner wall delimiting the gas path and at least one resonance cavity arranged between the outer wall and the inner wall, the inner wall being pierced with holes for placing the gas path in fluidic communication with the at least one resonance cavity for the attenuation of noise; and upstream and downstream transverse walls which close the at least one resonance cavity at upstream and downstream ends of the at least one resonance cavity, respectively, wherein the upstream and downstream transverse walls define upstream and downstream apertures of the duct, respectively, wherein the holes have substantially equal diameters, and wherein the duct guides the gas from upstream to downstream, and a number of the holes per unit of surface area of the inner wall reduces continuously along the gas path, from upstream to downstream, to confer on the inner wall a substantially constant acoustic resistance along the gas path.