Broadband micro-perforated board sound absorber, absorber performance prediction method and absorber structure design method

A technology for micro-perforated plates and performance prediction, which is applied in computing, sound-generating equipment, instruments, etc., and can solve the problems that local resonance effects cannot be formed, and broadband micro-perforated plate sound absorbers have not yet been found.

CN105427853AActive Publication Date: 2016-03-23SOUTHEAST UNIV
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2016-03-23

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Abstract

The invention discloses a broadband micro-perforated board sound absorber, a sound absorber performance prediction method and a sound absorber structure design method. The sound absorber comprises a surface micro-perforated board and a back chamber with unequal periodicity depth, and the back chamber is used for expanding sound absorption bandwidth of the sound absorber. The performance prediction method is used for predicting a sound absorption coefficient frequency spectrum of the sound absorber, through finite element simulation and experiment measurement verification, the performance prediction method is accurate and reliable; the structure design method used for effectively realizing the broadband micro-perforated board sound absorber comprises steps that (1), a depth matrix of the periodic back chamber is designed on the basis of the secondary residual sequence combination arrangement theory; and (2), evaluation is realized on the basis of the performance prediction method, combination of parameters of the sound absorber are sequentially determined, including total sound absorber width of the periodic back chamber, depth of each sub back chamber, board thickness of the micro-perforated board, aperture and perforated percentage. Through the sound absorber performance prediction method and the sound absorber structure design method, the micro-perforated board sound absorber having the broadband sound absorption performance can be accurately, reliably and simply designed.
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Description

technical field

[0001] The invention relates to the field of environmental noise control and sound absorption of indoor acoustic decoration, in particular to a wide-band high-performance micro-perforated plate sound-absorbing body and its performance prediction and structural design methods. Background technique

[0002] At present, a typical micro-perforated panel sound absorber consists of a single-layer uniformly perforated micro-perforated panel and its corresponding single panel rear cavity. Different from the sound-absorbing materials of traditional porous materials and fiber materials, it has a simple structure, and the structure can be made of various materials, such as metal, plastic, wood and even glass. The advantages include no debris after long-term use, the surface can resist impact, moisture and water, and can adapt to high-speed airflow, etc. It is an environmentally friendly new sound-absorbing material. However, a prominent problem in the application of th...

Examples

Embodiment 1

[0046] A broadband micro-perforated sound-absorbing body, comprising: a micro-perforated plate 1, sub-back cavities with different depths are arranged on the micro-perforated plate 1, and the sub-back cavities stand on the micro-perforated plate 1, and the corresponding Adjacent to the side of the microperforated plate 1. In this embodiment, six sub-chambers with different depths are provided on the micro-perforated plate 1 .

Embodiment 2

[0048] A method for predicting the performance of a broadband micro-perforated plate sound absorber, the performance is determined by the sound absorption coefficient spectrum α(θ e ) characterization, the sound absorption coefficient spectrum α(θ e ) is obtained by formula 1,

[0049] α ( θ e ) = 1 - | A 0 P e | 2 - 1 cosθ e Σ n ≠ 0 | A n P e ...

Embodiment 3

[0066] A structural design method for sound-absorbing body design using a performance prediction method, comprising the following steps:

[0067] Step 1 obtains the sound spectrum to be absorbed, and then obtains the target effective sound absorption spectrum range in the sound absorption coefficient spectrum, and it is generally considered that the sound absorption frequency band with a sound absorption coefficient above 0.45 is the effective sound absorption spectrum range;

[0068] Step 2 Select the material of the micro-perforated plate and the sub-back cavity, set the surface acoustic impedance of the micro-perforated plate to 0.5-1.5 times the air acoustic impedance, and use the calculation method of the acoustic impedance of the micro-perforated plate to determine the parameters of the micro-perforated plate, the perforation diameter d and the thickness of the plate The initial value of t and the perforation rate i;

[0069] Step 3 Design the depth matrix of the sub-bac...