Abstract
Room surfaces have been extensively modeled as locally reacting in room acoustic predictions although
such modeling could yield significant errors under certain conditions. Therefore, this study aims to propose
a guideline for adopting the local reaction assumption by comparing predicted random incidence acoustical
characteristics of typical building elements made of porous materials assuming extended and local reaction.
For each surface reaction, five well-established wave propagation models, the Delany-Bazley, Miki,
Beranek, Allard-Champoux, and Biot model, are employed. Effects of the flow resistivity and the absorber
thickness on the difference between the two surface reaction models are examined and discussed. For a
porous absorber backed by a rigid surface, the local reaction models give errors of less than 10% if the
thickness exceeds 120 mm for a flow resistivity of 5000 Nm-4s. As the flow resistivity doubles, a decrease
in the required thickness by 25 mm is observed to achieve the same amount of error. For an absorber
backed by an air gap, the thickness ratio between the material and air cavity is important. If the absorber
thickness is approximately 40% of the cavity depth, the local reaction models give errors below 10% even
for a low flow resistivity case.
Original language | English |
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Title of host publication | INTER- NOISE 2011 Proceedings |
Publication date | 2011 |
Publication status | Published - 2011 |
Event | INTER-NOISE 2011 : 40th International Congress and Exposition on Noise Control Engineering - Osaka, Japan Duration: 4 Sep 2011 → 7 Sep 2011 Conference number: 40 |
Conference
Conference | INTER-NOISE 2011 : 40th International Congress and Exposition on Noise Control Engineering |
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Number | 40 |
Country/Territory | Japan |
City | Osaka |
Period | 04/09/2011 → 07/09/2011 |
Keywords
- Local reaction
- Random incidence absorption
- Extended reaction