On the acoustic wedge design and simulation of anechoic chamber

Jiang, Changyong; Zhang, Shangyu; Huang, Lixi

doi:10.1016/j.jsv.2016.06.020

Cited by 8 publications

(5 citation statements)

References 25 publications

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“…Unobstructed sound can be created when the wave is not affected much by behaviors such as reflection, absorption, deflection, diffraction, refraction, diffusion and is not affected by the effects of resonance [8]. Literature studies conducted by many researchers state that the selection of the medium material and the shape of the wedges significantly affect the absorption performance to produce a space without echo [9,10,11]. The perfect free-reflection of sound in anechoic chamber design provides precise measurement of noise source sound power levels, this condition is also ideal for calibrating electro-acoustic measuring instruments and measuring the performance of various electroacoustic products [12,13,14].…”

Section: 𝐿mentioning

confidence: 99%

Computational investigation of various wedges electromagnetic wave absorbers on anechoic chambers

Afkar

2022

Sinergi

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The anechoic chamber is closely related as a device for precisely measuring various acoustic characteristics. Anechoic chambers room conditions controlled to produce a sound field-free space. This study focused on testing various commercial wedges such as Eckel, diamond, pyramidal, and oblique pyramidal. The test was done by varying the elevation of an incident angle at 0°-85° with a stepping distance is 5°. This study is analyzed at 1-3 GHz frequency. This research was conducted based on a computational analysis using the finite element method on electromagnetic wave physics interfaces using COMSOL Multiphysics. The results show that, in general, pyramidal has the best performance. These results are assessed from the stability of absorption performance, the Eckel model obtains -66.6 dB at 1 GHz frequency but on another frequency tests with drastic performance fluctuations. In general, a pyramidal model can be an ideal absorber for anechoic applications because it provides good absorption performance for near normal and normal incidence angles. The results of the design and testing of the wedges model for anechoic are expected to be references in designing the optimal anechoic chamber room. Furthermore, it can contribute positively to tuning acoustic instruments such as microphones or reducing the antenna measurement error.

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Section: 𝐿mentioning

confidence: 99%

Computational investigation of various wedges electromagnetic wave absorbers on anechoic chambers

Afkar

2022

Sinergi

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“…The absorption coefficient can be acquired from the fitness function. In this optimization, the absorber, which is considered optimum, has the following conditions:  Absorption coefficient > 0.99 [3,5,6]  Absorber length < 100 cm [5,6]  Cut-off frequency < 100 Hz [1,3] These conditions are used to be termination conditions. As termination conditions, these three conditions must be met by GA to terminate GA loops and get the optimization results.…”

Section: Termination Conditionmentioning

confidence: 99%

“…Research conducted by experts also varies, ranging from the size of the room [5], materials [3], and the geometric shapes used [6]. The research that has been done is based on field tests [7] and simulations [6,8]. Research on anechoic chambers resulted in two standards known as ISO 3745 and ISO 26101.…”

Section: Introductionmentioning

confidence: 99%

Absorber Geometry Size Optimization For Acoustic Anechoic Chamber Design Using Genetic Algorithm

Christian

Suprayogi

Fitriyanti

2022

J. Phys.: Conf. Ser.

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An anechoic chamber is a room that is made to resemble the condition of empty space. This room has an absorption rate of 99%. The absorber is an essential part while manufacturing an anechoic chamber. In an anechoic chamber, absorber affects in terms of absorption and frequency range. Specification of the absorber used depends on the specification of the anechoic chamber to be made. The optimum absorber geometry size is required to maximize the net volume of the anechoic chamber. The maximum measurable object size is 0.05x net volume of an anechoic chamber. To overcome the problem, it is necessary to optimize the size of the absorber geometry. The size optimization of the absorber geometry has been carried out using a genetic algorithm with MATLAB as the programming software. The incidence angle of the wave and the width of the absorber are used as input parameters for absorber optimization. Absorber geometry size optimization results in an optimum peak angle and absorber length. The width of the absorber used in this optimization is 0.2 m. The peak angle obtained is 12.2° with a length of 0.936 m. The average absorption coefficient obtained is 0.886041.

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“…As a result, it is critical to develop ideal sound absorbers for the anechoic chamber that have the highest sound absorption while being the thinnest. The sound absorbers of the anechoic chamber could be flat, 4 wedge, 5 conical, 6 or pyramidshaped. 1 Wave method, 7 numerical methods (like the finite element method 6,7 and finite difference time-domain method 8 ) and experimental methods (including measuring the sound absorption coefficient of perpendicular impact in the impedance tube [9][10][11][12] and the actual sound absorption coefficient in the reverberation room 1 ) can be used to determine the absorption coefficient of sound absorbers.…”

Section: Introductionmentioning

confidence: 99%

“…Jiang et al 4 proposed a uniform-then-gradient flat-wall (UGFW) structure as an absorber material that has a varying flow resistivity throughout the absorber thickness. The acquired results showed that using this structure decreases the thickness of the absorber by 4 cm while maintaining the same 100 Hz cut-off frequency.…”

Section: Introductionmentioning

confidence: 99%

Analysis and optimization of the chamfered pyramid and evaluation of geometrical parameters’ effect on its sound absorption coefficient

Moradi,

Basirjafari

2024

Building Acoustics

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Since symmetrical geometry makes it easier to arrange pyramid absorbers on anechoic chamber walls compared to wedge absorbers, the goal of this paper is to present an optimal pyramid-shaped absorber which, in addition to the optimal performance in sound absorption, has other advantages such as less thickness, lower material consumption and cost, easier construction, arrangement and maintenance and occupying less space compared to wedges. The COMSOL Multiphysics software was used to simulate the optimized sound absorber by using the genetic algorithm programed in MATLAB software, with the goal of a 100 Hz cut-off frequency. The results show that the optimized chamfered pyramid at the top performs better at sound absorption compared to the complete pyramid and wedge with 18% less thickness. Furthermore, the cut-off frequency decreased to 91 Hz when a gap of up to 15 mm was created between the adjacent absorbers mounted on the surface, which is desirable.

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On the acoustic wedge design and simulation of anechoic chamber

Cited by 8 publications

References 25 publications

Computational investigation of various wedges electromagnetic wave absorbers on anechoic chambers

Computational investigation of various wedges electromagnetic wave absorbers on anechoic chambers

Absorber Geometry Size Optimization For Acoustic Anechoic Chamber Design Using Genetic Algorithm

Analysis and optimization of the chamfered pyramid and evaluation of geometrical parameters’ effect on its sound absorption coefficient

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