NOISE MUFFLER ELEMENT Russian patent published in 2018 - IPC F01N1/04 

FIELD: engines and pumps, acoustics.

SUBSTANCE: invention relates to compressor stations and test boxes noise suppression equipment for gas turbine engines. Muffler contains a cylindrical frame in the form of a perforated sleeve and covers, filled with a sound absorber, and from the outside of the sleeve there is a layer of an acoustically transparent shell made of a nylon mesh or fiberglass, and the frame comprises caps with annular beads for securing the cylindrical sleeve, while the lids are connected by a central rod to the hooks at both ends, and the cylindrical bushing consists of two perforated shells – external and internal, the space between them is filled with a sound-absorbing element, the sound-absorbing element is made in the form of symmetrically arranged perforated walls, between which there is a multilayer sound absorber, made in the form of three layers: a central layer of a sound-reflecting material of a complex profile with a perforation, made of uniformly distributed hollow tetrahedra, that allow to reflect the sound waves that fall in all directions, and the perforation acoustically connects it with the sound-absorbing layers symmetrically adjacent to it from sound-absorbing materials of different densities, the perforation is made in the form of the Helmholtz resonator cavities, the volume of which is the space enclosed between the surfaces of the sound-absorbing layers and the central layer of the complex profile.

EFFECT: higher efficiency of noise suppression.

1 cl, 2 dwg