Abstract
The sound transmission loss of a conventional expansion chamber is limited by its length and the area ratio. This phenomenon can be improved by appropriate staggering of the sub-chambers as shown in a previous study. However, the sound transmission loss will be reduced in the presence of a low Mach number duct flow. In the present study, the sound transmission losses across expansion chambers formed by two staggered chambers in the presence of low Mach number turbulent flows of velocities between 0 to 20 m/s were measured experimentally. Pressure measurements are also carried out simultaneously with the sound transmission loss measurements for a better understanding on the correlation between incident sound and the sound pressure within the chambers. It is found that the frequencies of high sound transmission loss correspond to those where a low pressure region in the chambers is observed. The increase in flow velocity makes such correlation less distinctive. Large scale shear layer rollup is not observed in this velocity range.
Original language | English |
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Title of host publication | INTER-NOISE 2015 - 44th International Congress and Exposition on Noise Control Engineering |
Publisher | The Institute of Noise Control Engineering of the USA, Inc. |
Publication status | Published - 1 Jan 2015 |
Event | 44th International Congress and Exposition on Noise Control Engineering, INTER-NOISE 2015 - San Francisco Marriott Marquis Hotel, San Francisco, United States Duration: 9 Aug 2015 → 12 Aug 2015 |
Conference
Conference | 44th International Congress and Exposition on Noise Control Engineering, INTER-NOISE 2015 |
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Country/Territory | United States |
City | San Francisco |
Period | 9/08/15 → 12/08/15 |
ASJC Scopus subject areas
- Acoustics and Ultrasonics