Continuously and gradually enlarging gradient punching double-porosity sound absorbing device and application thereof

A sound-absorbing device and double-aperture technology, which is applied in the direction of sound-emitting devices, instruments, floors, etc., to achieve the effect of improving low-frequency sound absorption capacity, good broadband sound absorption performance, and excellent sound absorption performance

Active Publication Date: 2019-05-03
XI AN JIAOTONG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] The technical problem to be solved by the present invention is to provide a continuous gradual expansion gradient opening double porosity sound absorption device...

Method used

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  • Continuously and gradually enlarging gradient punching double-porosity sound absorbing device and application thereof
  • Continuously and gradually enlarging gradient punching double-porosity sound absorbing device and application thereof
  • Continuously and gradually enlarging gradient punching double-porosity sound absorbing device and application thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0049] see figure 1 and figure 2 , periodically open frustum holes in a perforated porous material plate 1 with a total height of 60mm, the porosity of the base porous material is 90%, and the flow resistance is 47700N·s / m 2 , the viscous characteristic length is 24 μm, the thermal characteristic length is 200 μm, and the tortuosity is 1.29; the apertures at both ends of the frustum hole are 30 mm and 6 mm respectively, and the opening ratio of the sound-absorbing board (the total volume of the openings accounts for the total volume of the board without openings) Volume) is 17.58%; one side of the small end face of the frustum hole of the perforated porous material plate 1 is placed on the rigid backing, so as to simulate that the designed sound-absorbing material is closely attached to the indoor wall, the wall surface of the transportation vehicle and the inside of the machine. condition of the wall.

[0050] see figure 2 , compared with the same substrate material and ...

Embodiment 2

[0052] Set the aperture diameter of the frustum hole in Implementation 1 to 6mm and 3mm, at this time, the opening rate of the sound-absorbing panel is 4%, and the parameters of the base porous material and other structural parameters remain unchanged. Similarly, the perforated porous material panel 1 One side of the small end of the frustum hole is placed on the rigid backing to simulate the situation where the designed sound-absorbing material is attached to the indoor wall, the wall of the transportation vehicle and the inner wall of the machine. The sound absorption coefficient of embodiment 2 of the present invention sees image 3 , compared with the same substrate material and the same thickness of uniform porous material plate without openings, this embodiment can appear earlier at the frequency of 510Hz sound absorption peak, the peak sound absorption coefficient is 0.85, and in the range above 220Hz to achieve Enhanced sound absorption.

Embodiment 3

[0054] Set the aperture diameter of the frustum hole in Implementation 1 to 23mm and 4mm, at this time, the opening rate of the sound-absorbing panel is 40%, and the parameters of the base porous material and other structural parameters remain unchanged. Similarly, the perforated porous material panel 1 One side of the small end of the frustum hole is placed on the rigid backing to simulate the situation where the designed sound-absorbing material is attached to the indoor wall, the wall of the transportation vehicle and the inner wall of the machine. The sound absorption coefficient of embodiment 3 of the present invention sees Figure 4 , compared with the same substrate material and the same thickness of the uniform porous material plate without openings, the sound absorption peak appears earlier at the frequency of 1490Hz in this embodiment, the peak sound absorption coefficient is close to 1, and the sound absorption coefficient is close to 1, and the sound absorption is a...

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Abstract

The invention discloses a continuously and gradually enlarging gradient punching double-porosity sound absorbing device and application thereof. A porous material is adopted as a substrate of a perforated porous material plate, gradient holes are periodically formed in the perforated porous material plate, the punching direction is perpendicular to the perforated porous material plate, the punching pore diameter continuously become larger or smaller in the thickness direction, and according to actual requirements, the gradient double-porosity sound absorbing plate can be directly placed on rigid backing, or a hollow cavity is reserved between the sound absorbing plate and the rigid backing to further improve the sound absorbing property. The continuously and gradually enlarging gradient punching double-porosity sound absorbing device is simple and practical in structure, has a superior sound absorbing property and a flexible sound absorbing adjusting function in a low frequency band, amedium frequency band and a high frequency band, and has good and wide application prospects.

Description

technical field [0001] The invention belongs to the technical field of building materials, and in particular relates to a continuous gradually expanding gradient opening double porosity sound absorption device and its application. Background technique [0002] The existing sound-absorbing panel is a plate-shaped material with sound-absorbing and noise-reducing functions, and is mainly used in scenes such as concert halls, museums, libraries, and inner walls of vehicles. Traditional sound-absorbing panels mainly absorb sound in two ways: one is to use porous fibers or foam materials for sound absorption, and the sound absorption coefficient increases with the increase of frequency, which is suitable for high-frequency sound absorption; the other is to use The micro-perforated plate of the cavity is used for sound absorption, which can have resonance sound absorption peaks at lower frequencies, and is suitable for middle and low frequency sound absorption. It is difficult for...

Claims

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Application Information

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IPC IPC(8): E04B1/82E04B1/86G10K11/16G10K11/162
Inventor 辛锋先刘学伟
Owner XI AN JIAOTONG UNIV
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