Surface configuration and acoustic impedance dicycle mutation microporous ultra-broadband sound absorption structure

Abstract

The invention relates to a surface configuration and acoustic impedance dicycle mutation microporous ultra-broadband sound absorption structure. By connection of microporous panels, unit partition plates, unit bottom plates, left end faces, right end faces, front end faces and rear end faces, closed cavities in periodic array are formed, the cavities in two depths are in periodic variation, and the larger depth is 1.5-3.5 times of the smaller depth. Micropores, in diameter of 0.2-1.2mm, accounting for 0.3%-3.5% of the area of each panel are distributed on each microporous panels, and unit width is not larger than 0.2m. The structure can be used only after being fixed to a wall surface of a place requiring sound absorption treatment. The structure is simple, thin, light, simple and convenient to process and excellent in sound absorption performance, sound absorption band width reaches three octaves while the acoustical absorption coefficient is within 2.5KHz, a peak value is close to 1.0, smoothness in sound absorption, wide applicability, easiness in cleaning, high temperature resistance, excellent weather resistance and complete recyclability are realized, and secondary pollutionis completely avoided due to freeness of fiber filler materials.

Description

technical field [0001] The invention belongs to the technical field of acoustics, in particular to a micro-perforated ultra-broadband sound-absorbing structure for medium and low-frequency noises and a double-period mutation of acoustic impedance. Background technique [0002] The problem of noise pollution is becoming more and more serious with the development of urban economy and the growth of population. The complaints caused by the impact of noise pollution on people account for more than 50% of all kinds of environmental complaints in economically developed cities. With the advancement of urbanization, the increasing social activities and the use of equipment make people's living environment have obvious low-frequency characteristics, which often causes people to feel annoyed subjectively when the sound pressure level of environmental noise has not reached the standard limit. Low-frequency noise can significantly interfere with people's thinking ability and affect peopl...

AI Technical Summary

Problems solved by technology

[0005] However, for ordinary resonant sound-absorbing structures with a single cavity, in order to have good sound-absorbing performance at low frequencies, the depth of the cavity must be greatly increased, and the volume is often large

In addition, the common resonant sound-absorbing structure with a single cavity has a narrow sound-absorbing frequency band. For a micro-perforated plate with a pore size of 1 mm, the half-sound-absorbing bandwidth (sound absorption coefficient ≥ 0.5) is usually less than 2 octaves

The lower the sound-absorbing frequency requirement, the greater the thickness of the sound-absorbing structure. In situations where the space is generally limited, ordinary resonant sound-absorbing structures cannot well meet the actual needs of noise control.

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