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
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Online Access:http://psasir.upm.edu.my/id/eprint/40914/1/FK%202010%2045R.pdf
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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
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