Low-frequency broadband multi-layer sound-absorbing device with small mechanical unit planar array

Abstract

The invention discloses a low-frequency broadband multi-layer sound-absorbing device of a plane array of small mechanical units, which belongs to the technical field of noise control. Its feature is that in front of the back wall that needs to reduce sound wave reflection, layers of acoustic materials and planar arrays of small mechanical units are alternately installed to achieve low-frequency broadband sound absorption. The planar array of small mechanical units is formed by periodically embedding small mechanical units on the board. The small mechanical unit is composed of a frame, a sound wave input component, a forward amplification mechanism or a reverse amplification mechanism, a sound wave output component, and a damper or damping material. The acoustic material layer adopts porous sound-absorbing material, and the acoustic impedance of each layer is different. Among them, the planar array of small mechanical units, on the one hand, reduces the size of the sound-absorbing structure through impedance transformation, and on the other hand, through the acoustic resonance of the small mechanical array and the acoustic material layer, the damper is used to achieve low-frequency broadband sound absorption. The effect and benefit of the present invention are that, in terms of working principle, it is quite different from the existing multi-layer sound-absorbing structure, and has great advantages in low-frequency broadband absorbing, and is especially suitable for the stealth of underwater submarines.

Description

technical field [0001] The invention belongs to the technical field of environmental noise control and relates to a low-frequency broadband multi-layer sound-absorbing structure, in particular to a low-frequency broadband multi-layer sound-absorbing device suitable for underwater submarine stealth and small mechanical unit plane array. Background technique [0002] At present, many scholars and engineers at home and abroad are conducting research on multi-layer sound-absorbing structures, either for civilian or military use. Generally speaking, the relevant literature and patents at home and abroad are mainly based on sound-absorbing materials or Helmertz resonant cavities to design broadband sound-absorbing structures. In the air, micro-perforated plates or porous sound-absorbing materials are generally used to design sound-absorbing structures, and in water, hydroacoustic rubber with special hole patterns is generally used to design sound-absorbing tiles. However, these s...

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So far, there have been no research reports, documents or patents on the multi-layer sound-absorbing structure embedded in the planar array of small mechanical units at home and abroad.

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