The device of the reduction of the noise issued by a pipe and leads to 371 relates to such a device

摘要

The device for reducing the noise emitted by a pipe (1) belonging to a system of an aircraft, comprises an acoustic gate (6) disposed in a portion of the duct. This gate has a length l1, along the axis (x - x) of said section, and comprises a plurality of openings (9), each of which is inscribed in a square of side m, the following conditions are fulfilled: l1 1,8 λ fmin m & λ fmax / 2, where fmax is the maximum frequency of the noise to be attenuated, fmin is the minimum frequency of the noise to be attenuated, λ fmax is the wavelength of the noise at the frequency fmax, and λ fmin is the wavelength of the noise at the frequency fmin. Application to the inlet and outlet ducts of air of the systems for aircraft.