Numerical modeling and minimization of enclosure interior noise using local active sound control

Low frequency noise has detrimental effects on human’s physiology and psychology. To reduce low frequency noise, active control of sound is more effective compared to passive sound absorbers. Reduction of low frequency noise in structures like vehicle cabin and room in a house is therefore important...

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Main Author:	Mohamady, Samira
Format:	Thesis
Language:	English
Published:	2010
Subjects:	Noise control - Mathematical models Soundproofing
Online Access:	http://psasir.upm.edu.my/id/eprint/40914/1/FK%202010%2045R.pdf
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id	my-upm-ir.40914
record_format	uketd_dc
spelling	my-upm-ir.409142015-10-05T03:39:12Z Numerical modeling and minimization of enclosure interior noise using local active sound control 2010-08 Mohamady, Samira Low frequency noise has detrimental effects on human’s physiology and psychology. To reduce low frequency noise, active control of sound is more effective compared to passive sound absorbers. Reduction of low frequency noise in structures like vehicle cabin and room in a house is therefore important. These structures can be modeled as a three dimensional (3D) enclosure with a flexible boundary structure on one of its side. In this thesis minimization of sound pressure in an enclosure with five rigid walls and a flexible plate on its top side using local active noise control technique was investigated. The acoustic environment of the enclosure was modeled using the finite element method. COMSOL© MULTIPHYSICS software which provides structural and acoustical modules was used to create finite element model of the enclosure. Modal analysis of this system was performed and the eigenfrequencies were compared against those obtained in related analytical and experimental works. In order to verify the finite element modeling procedure, convergence analysis of the system was performed. The eigenfrequencies of the finite element model were compared with the ones obtained for analytical and experimental models and the mean absolute error of 5.8 % and 4.3 % were achieved respectively. Local control method has been used to design the controller in reducing the interior sound pressure field at two observer locations. The estimated noise reduction was assessed by calculating the estimated sound potential energy in the enclosure with and without controller. An average of 140.4 dB reduction in estimate potential energy in low frequency range has been obtained. Reduction of sound pressure at each observer position is around 60 dB. This implies that local active control of sound can be used in reducing sound pressure level at desired observer locations within the enclosure. Noise control - Mathematical models Deafness, Noise induced - Prevention Soundproofing 2010-08 Thesis http://psasir.upm.edu.my/id/eprint/40914/ http://psasir.upm.edu.my/id/eprint/40914/1/FK%202010%2045R.pdf application/pdf en public masters Universiti Putra Malaysia Noise control - Mathematical models Deafness, Noise induced - Prevention Soundproofing
institution	Universiti Putra Malaysia
collection	PSAS Institutional Repository
language	English
topic	Noise control - Mathematical models Noise control - Mathematical models Soundproofing
spellingShingle	Noise control - Mathematical models Noise control - Mathematical models Soundproofing Mohamady, Samira Numerical modeling and minimization of enclosure interior noise using local active sound control
description	Low frequency noise has detrimental effects on human’s physiology and psychology. To reduce low frequency noise, active control of sound is more effective compared to passive sound absorbers. Reduction of low frequency noise in structures like vehicle cabin and room in a house is therefore important. These structures can be modeled as a three dimensional (3D) enclosure with a flexible boundary structure on one of its side. In this thesis minimization of sound pressure in an enclosure with five rigid walls and a flexible plate on its top side using local active noise control technique was investigated. The acoustic environment of the enclosure was modeled using the finite element method. COMSOL© MULTIPHYSICS software which provides structural and acoustical modules was used to create finite element model of the enclosure. Modal analysis of this system was performed and the eigenfrequencies were compared against those obtained in related analytical and experimental works. In order to verify the finite element modeling procedure, convergence analysis of the system was performed. The eigenfrequencies of the finite element model were compared with the ones obtained for analytical and experimental models and the mean absolute error of 5.8 % and 4.3 % were achieved respectively. Local control method has been used to design the controller in reducing the interior sound pressure field at two observer locations. The estimated noise reduction was assessed by calculating the estimated sound potential energy in the enclosure with and without controller. An average of 140.4 dB reduction in estimate potential energy in low frequency range has been obtained. Reduction of sound pressure at each observer position is around 60 dB. This implies that local active control of sound can be used in reducing sound pressure level at desired observer locations within the enclosure.
format	Thesis
qualification_level	Master's degree
author	Mohamady, Samira
author_facet	Mohamady, Samira
author_sort	Mohamady, Samira
title	Numerical modeling and minimization of enclosure interior noise using local active sound control
title_short	Numerical modeling and minimization of enclosure interior noise using local active sound control
title_full	Numerical modeling and minimization of enclosure interior noise using local active sound control
title_fullStr	Numerical modeling and minimization of enclosure interior noise using local active sound control
title_full_unstemmed	Numerical modeling and minimization of enclosure interior noise using local active sound control
title_sort	numerical modeling and minimization of enclosure interior noise using local active sound control
granting_institution	Universiti Putra Malaysia
publishDate	2010
url	http://psasir.upm.edu.my/id/eprint/40914/1/FK%202010%2045R.pdf
_version_	1747811849099804672

Numerical modeling and minimization of enclosure interior noise using local active sound control

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