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

Abstract

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.

Keywords

Optimization sound absorber chamfered pyramid impedance tube genetic algorithm sound absorption coefficient

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References

Beranek

Sleeper

. The design and construction of anechoic sound chambers. J Acoust Soc Am 1946; 18: 140–150.

Koidan

Hruska

Pickett

. Wedge design for National Bureau of Standards Anechoic Chamber. J Acoust Soc Am 1972; 52: 1071–1076.

Salvado

Calado

Santo

. A simple yet effective semi-anechoic chamber for the acoustic characterization of an LSRA. IEEE Lat Am Trans 2013; 11(5): 1190–1200.

Jiang

Zhang

Huang

. On the acoustic wedge design and simulation of anechoic chamber. J Sound Vib 2016; 381: 139–155.

Tavakkoli Nejad

Loghmani

Ziaei-Rad

. The effects of wedge geometrical parameters and arrangement on the sound absorption coefficient – A numerical and experimental study. Appl Acoust 2020; 169: 107458 1–13.

Easwaran

Munjal

. Finite element analysis of wedges used in anechoic chambers. J Sound Vib 1993; 160: 333–350.

Fenemore

Kingan

Mace

. Application of the wave and finite element method to predict the acoustic performance of double-leaf cross-laminated timber panels. Build Acoust 2023; 30: 203–225.

Toyoda

Eto

. Prediction of microperforated panel absorbers using the finite-difference time-domain method. Wave Motion 2019; 86: 110–124.

de Melo

GDSV

Gibbs

Gerges

SNY

. Sound absorption at low frequencies: room contents as absorbers. Build Acoust 2007; 14: 283–309.

10.

Pöhler

Jetsu

Isomoisio

. Benchmarking new wood fibre–based sound absorbing material made with a foam-forming technique. Build Acoust 2016; 23: 131–143.

11.

Horoshenkov

Jin

. The influence of a thin, natural cellulose fibre membrane on the acoustic absorption of a layer of melamine foam. Build Acoust 2023; 30: 127–142.

12.

Iannace

Ciaburro

. Modelling sound absorption properties for recycled polyethylene terephthalate-based material using Gaussian regression. Build Acoust 2021; 28: 185–196.

13.

Lee

Kim

, et al. Two-dimensional poroelastic acoustical foam shape design for absorption coefficient maximization by topology optimization method. J Acoust Soc Am 2008; 123: 2094–2106.

14.

Delany

Bazley

. The high frequency performance of wedge-lined free field rooms. J Sound Vib 1977; 55: 195–214.

15.

Chen

Lee

Chiang

. On the acoustic absorption of porous materials with different surface shapes and perforated plates. J Sound Vib 2000; 237: 337–355.

16.

Bonfiglio

Pompoli

. Numerical methodologies for optimizing and predicting the low frequency behavior of anechoic chambers. J Acoust Soc Am 2013; 134: 285–291.

17.

Delany

Bazley

. Acoustical properties of fibrous absorbent materials. Appl Acoust 1970; 3: 105–116.

18.

ISO 10534-2. Acoustics — Determination of sound absorption coefficient and impedance in impedance tubes-Part 2: Transfer-function method.

19.

Broghany

Saffar

Basirjafari

. Increasing the frequency band of sound absorption for flat multi-layered absorbers consisting of porous material, perforated panel and air-gap. Am J Mech Eng 2018; 50: 219–230.

20.

Broghany

Basirjafari

Saffar

. Optimization of flat multi-layer sound absorber by using multi-objective genetic algorithm for application in anechoic chamber. Modares Mech Eng 2016; 16: 215–222.

21.

Broghany

Basirjafari

. Optimum design of multi-layered micro-perforated panel sound absorbers in combination with porous materials in an arbitrary frequency range. Int J Eng Trans B Appl 2022; 35: 996–1005.

22.

Garai

Pompoli

. A simple empirical model of polyester fibre materials for acoustical applications. Appl Acoust 2005; 66: 1383–1398.