RESONANT ACOUSTIC ABSORBER BY KOCHETOV Russian patent published in 2015 - IPC E04B1/84 

FIELD: machine building.

SUBSTANCE: resonant acoustic absorber comprises a rigid frame consisting of an upper active part and a lower reactive part. The reactive part is made as three coaxial and axisymmetrical resonant cylinders with their cavities being fitted by holes of different diameter serving as Helmholtz resonator necks. Supporting disks set at the cylinder ends connect the latter to each other in rigid and leaktight manner forming the reactive part of the rigid frame of the acoustic absorber. The upper active part is made in the form of a rigid perforated cylindrical shell with a perforated cover and a solid base. The cavity of the cylindrical shell is filled with sound absorbing material. At least one spiral acoustic absorbing element in the form of a cylindrical coil spring enclosing the shell is mounted around the perforated cylindrical shell. The upper and lower parts are interconnected by a resilient damping element.

EFFECT: improved efficiency of noise suppression at high frequencies.

2 cl, 1 dwg