Degree Type

Thesis

Date of Award

2018

Degree Name

Master of Science

Department

Mechanical Engineering

Major

Mechanical Engineering

First Advisor

Shan Hu

Abstract

With rising concern pertaining to sound pollution and how it affects public health, new technologies are being considered to ensure sound is effectively attenuated and human exposure to unwanted noise is minimized. One of these technologies that separate the source from the observer is called the partition. As single wall partitions have to be physically dense to provide robust sound attenuation, they are not an efficient solution. An alternative solution is called double wall partitions. Double wall assemblies are lightweight, low-cost alternatives to single wall partitions that provide powerful transmission loss. Despite this, the performance of these assemblies suffer at a frequency called the mass-air-mass resonance frequency. Acoustically reinforcing this assembly is important to ensure their performance over a large frequency range. Helmholtz resonators are powerful methods to block sound in a narrow frequency band, and thus seem perfect to implement in double panel windows. However, when implemented, around the immediate vicinity of the Helmholtz resonator resonance, the performance of the entire assembly deteriorates. In this study, the use of several panels of Helmholtz resonators as a double wall assembly is investigated. As two panels can be set up in several configurations, the new configurations provide additional degrees of freedom that can be used to tune these sound packages to perform well at certain frequencies. Using the transfer matrix method, several cases are simulated and investigated. In certain configurations, improvement of up to 20db is noticed at the Helmholtz resonator resonant frequency. Several cases are also studied for when a porous layer is incorporated into the system.

Copyright Owner

Sanvisna Kogelen

Language

en

File Format

application/pdf

File Size

60 pages

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