Spatial bending and sound absorption superstructure with impedance matching layers

Abstract

The invention discloses a spatial bending and sound absorption superstructure with impedance matching layers. The space bending and sound absorption superstructure comprises a perforated panel, a spatial bending back cavity with parameter gradient change, and a rigid backing, wherein the perforated panel and the rigid backing are located at the two ends of the spatial bending back cavity with theparameter gradient change; a plurality of sound absorption holes are formed in the perforated panel; the opening directions of the sound absorption holes are all perpendicular to the perforated panel;the hole diameters of the sound absorption holes are submillimeter-sized; the spatial bending back cavity with the parameter gradient change is composed of an internal spiral structure and an outer cylinder; and the internal spiral structure is composed of the upper impedance matching layer, the lower impedance matching layer and a narrow and long spiral structure. The bending back cavity is composed of the narrow and long bending structure in the middle and the impedance matching layers at the two ends, and the shapes of the narrow and long bending structure and the impedance matching layersare controlled by a simple parameter equation set and are easy to adjust; the sound absorption superstructure is simple and practical; the sound absorption wave peak in the impedance matching frequency band is remarkably widened, so that the impedance mismatching problem of the spatial bending structure is greatly improved; and the superstructure has good and wide application prospects.

Description

technical field [0001] The invention relates to the technical field of building materials, in particular to a space-bending sound-absorbing superstructure with an impedance matching layer. Background technique [0002] The existing space bending sound-absorbing superstructure is a sound-absorbing and noise-reducing structure that uses space bending to increase the depth of the back cavity to achieve low-frequency sound absorption, and can effectively reduce the thickness of the traditional micro-perforated sound-absorbing structure. However, the general space bending sound-absorbing superstructure generally has the disadvantage of impedance mismatch, which leads to an extremely narrow frequency bandwidth of low-frequency sound absorption. Contents of the invention [0003] In order to avoid the deficiencies of the prior art and overcome the extremely narrow low-frequency sound-absorbing frequency band of the space-bent sound-absorbing superstructure, the present invention ...

AI Technical Summary

Problems solved by technology

However, the general space bending sound-absorbing superstructure generally has the disadvantage of impedance mismatch, resulting in extremely narrow frequency bandwidth of low-frequency sound absorption.

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