Study of sound attenuation in elliptic ducts
type: CreativeWork
description: The acoustic emission resulting from the reciprocating motion of machinery parts, such as the movement of pistons and the intake/exhaust of gases in an automotive engine, or the pressure pulsation generated in compressors cause noise pollution. Passive noise--attenuating devices such as mufflers are usually employed in the intake or the exhaust flow path of such systems. A typical muffler element consists of an expansion chamber with inlet and outlet ports for the passage of the exhaust fluid. The difference in the size of the ports from the chamber dimensions presents an impedance mismatch to the propagating acoustic wave, resulting in partial or complete reflection of the sound energy. Mufflers can broadly be classified as reactive type or dissipative type. Reactive mufflers employ the principle of impedance mismatch by incorporating area changes in the transmission path. Dissipative mufflers usually have some kind of absorptive lining that converts sound energy into heat. In comparison to reactive mufflers, dissipative mufflers usually have a sound attenuation over a wider frequency range. However, pressure drop and particle clogging limit their application. The sound attenuation characteristics of a muffler is dependent on various factors like shape and size of the muffler, orientations of inlet/ outlet ports, and number of inlet/outlet ports. Since the parameter space involved is potentially very large, only a few muffler geometries have been extensively studied in the past, viz. circular or rectangular chamber mufflers. More recently, mufflers having elliptical cross-sections have received some attention. These types of mufflers require smaller space across one of the dimensions, and are suitable for applications where space constraints are an important design consideration. The existing literature on elliptic reactive mufflers is not extensive; therefore, further attention to this geometry is required. The present work aims to study the sound attenuation in e…
abstract: The acoustic emission resulting from the reciprocating motion of machinery parts, such as the movement of pistons and the intake/exhaust of gases in an automotive engine, or the pressure pulsation generated in compressors cause noise pollution. Passive noise--attenuating devices such as mufflers are usually employed in the intake or the exhaust flow path of such systems. A typical muffler element consists of an expansion chamber with inlet and outlet ports for the passage of the exhaust fluid. The difference in the size of the ports from the chamber dimensions presents an impedance mismatch to the propagating acoustic wave, resulting in partial or complete reflection of the sound energy. Mufflers can broadly be classified as reactive type or dissipative type. Reactive mufflers employ the principle of impedance mismatch by incorporating area changes in the transmission path. Dissipative mufflers usually have some kind of absorptive lining that converts sound energy into heat. In comparison to reactive mufflers, dissipative mufflers usually have a sound attenuation over a wider frequency range. However, pressure drop and particle clogging limit their application. The sound attenuation characteristics of a muffler is dependent on various factors like shape and size of the muffler, orientations of inlet/ outlet ports, and number of inlet/outlet ports. Since the parameter space involved is potentially very large, only a few muffler geometries have been extensively studied in the past, viz. circular or rectangular chamber mufflers. More recently, mufflers having elliptical cross-sections have received some attention. These types of mufflers require smaller space across one of the dimensions, and are suitable for applications where space constraints are an important design consideration. The existing literature on elliptic reactive mufflers is not extensive; therefore, further attention to this geometry is required. The present work aims to study the sound attenuation in e…
author: Banerjee, Subhabrata
keywords: Sound radiation, Transmission loss, Muffler, Acoustics
date published: 2015-07-22T22:16:01Z
date modified: 2026-07-22T22:26:11Z
provider: University of Illinois - Urbana-Champaign
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Illinois at Urbana-Champaign

PropertyValue
property ID: Handle
value: http://hdl.handle.net/2142/78323