The noise-attenuating device, such as an acoustic liner for an aircraft engine nacelle (fig 3), has a perforated facing sheet 36 with a coating 48 applied thereto. The coating defines an exposed surface for direct exposure to the environment in which noise attenuation is desired. By extending into the holes 44 the coating also defines a flared or bell-mouth-shaped entrance to one or more of the holes. The diameter of the holes may lie in the range 0.5 – 2.0 mm and the coating thickness may lie in the range 0.1 – 0.4 mm. The coating thickness may lie in the range between 5% and 20% of the hole diameter.
Noise-attenuating device and method of manufacture
2021-04-07
Patent
Electronic Resource
English