Investigation on micro-perforated panel absorber with ultra-micro perforations

Yu, Qian; Kong, Deyan; Liu, S.M.; Sun, Shao Ming; Zhao, Zhan

doi:10.1016/j.apacoust.2013.01.009

Cited by 94 publications

(45 citation statements)

References 7 publications

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“…It must be pointed out that typical MPEs have diameters ≈ 300 − 700µm, porosities ≈ 1 and thickness t ≈ 0.5mm. Aperture diameters smaller than ≈ 300 − 400µm accompanied by higher porosities can be technologically demanding, as for the case described in [13]. From this point of view the MPE1 can be considered already as less cost-effective than typical MPEs because of the reduced diameter of the perforations and the density of ≈ 22 holes per square centimetre necessary to provide porosity σ = 1.53%.…”

Section: Absorption Coefficientmentioning

confidence: 99%

“…Improvement of the absorption coefficient has been documented when the MPEs are utilized in combination with partitioned back cavities [10], as well as in multiple leaf configurations [11], or backed by Helmholtz resonators [12]. In [13], the acoustic performance of typical MPEs has been improved by utilizing ultra-micro perforation with diameter less then 100µm based on MEMS technology. In fact, as described by Maa in [7], a straightforward and space-saving way to approach the broadband absorption is to reduce the perforation diameter and increase the perforation ratio adequately.…”

Section: Introductionmentioning

confidence: 99%

“…Since the MGEs are based on a number of micro-channels engraved on the surface of two slotted mating plates, the manufacturing process is technologically effective. Nevertheless, the depth of the micro-channels can be easily < 100µm, as some of the ultra-micro perforated element presented in [13], while still preserving an adequate perforation ratio. Thus, the exhibited absorption coefficients can reach higher values than that of the traditional MPEs provided with 300 − 700µm perforation diameter.…”

Section: Introductionmentioning

confidence: 99%

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Acoustic performance of micro-grooved elements

Auriemma

2017

Applied Acoustics

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The acoustic performance of a new type of fibre-less sound absorber, the Micro-Grooved Element (MGE), is studied in this paper. The transfer impedance and the absorption coefficient of micro-grooved and Micro-Perforated Elements (MPEs) are measured, modelled and compared.A MGE is a double layer element that involves inlet/outlet slots and facing micro-channels engraved onto the mating surface of the layers. The main advantage of these elements is that, by means of a simple technological process, thin micro-channels with depth of less then 100µm can be easily engraved. This allows the MGEs exhibiting higher absorption coefficients compared to traditional MPEs with 300−700µm diameter of perforations. Moreover, due to the presence of surfaces surrounding the micro-channels, the MGEs show reduced resistance when exposed to high level of sound excitation. In this perspective, the performance of a MGE is more stable than the one of a MPE provided with the same porosity.A number of different MGEs with varied internal geometries has been tested at different excitation levels. The acoustics of the micro-channels is treated in details, the impedance end corrections are determined and the non-linear effects are accounted for. The linear behaviour of MGEs is described by adapting the models for slit-shaped perforated elements (SSEs). The quasi-and non-linear behaviours are expressed as a function of the Shear number and Strouhal number by curve fitting the experimental results.

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Section: Absorption Coefficientmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Acoustic performance of micro-grooved elements

Auriemma

2017

Applied Acoustics

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“…Multiple peaks can be obtained from such system and a wider absorption can be obtained accordingly. Recently, Qian et al [15] did an experimental investigation on the effect of reducing the perforation diameter of MPP to less than 100 m  . It was found that half-absorption bandwidth of 3-4 octaves with the peak absorption higher than 0.85 were pronounced.…”

Section: Introductionmentioning

confidence: 99%

Study on inhomogeneous perforation thick micro-perforated panel sound absorbers

Prasetiyo¹,

Sarwono²,

Sihar³

2016

J. MECH. ENG. SCI.

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Micro-perforated panel (MPP) sound absorbers are usually made of a thin panel and have narrow absorption bandwidth. This drawback causes the application of MPP to be limited. In this paper, the possibility of realizing wider absorption bandwidth MPP with sufficient structural strength is investigated. For this, multi-MPP (resonator) arranged in parallel to form an inhomogeneous perforation MPP is introduced to widen the absorption bandwidth. The thickness of MPP must be 1.5 times higher than perforation diameter or more in order to have appropriate strength. The characteristics of corresponding absorption coefficients are studied parametrically using theoretical models as thick panels can reduce the MPP's performance. It is found that the absorption bandwidth of thicker panels with inhomogeneous perforation approach can be at least twice times of classical MPP. The problem of reduced peak absorption coefficient in a thick panel can be avoided by keeping the acoustic resistance value around 1± 0.5 Rayls. Compared with homogeneous MPP, inter-resonator interaction exists in the inhomogeneous perforation thick MPP that causes the overall absorption to become higher due to the increasing of the acoustic resistance as well as the shifting of peak resonance following residual acoustic reactance. The measurement results confirm all of the characteristics.

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“…As an acoustic structure, perforated plates show excellent abilities for low-and middle-frequency noise control. Perforated plates [10,11] and mic-perforated plates [12,13] have been used to control noise in extensive ranges for years. Researchers filled porous materials into the back air layer of perforated plates to improve their sound absorption properties in highfrequency range [14,15].…”

Section: Introductionmentioning

confidence: 99%