0
TECHNICAL PAPERS

Bulk Reaction Modeling of Sound Propagation Through Circular Dissipative Ducts Backed by an Air Gap

[+] Author and Article Information
Sashindra K. Kakoty1

Department of Mechanical Engineering, IIT Guwahati, North Guwahati, Guwahati-781039, Assam, Indiaskkakoty@hotmail.com

Vinay K. Roy2

Department of Mechanical Engineering, IIT Guwahati, North Guwahati, Guwahati-781039, Assam, Indiavinay-iitg@rediffmail.com

1

Corresponding author.

2

Present address: Aerospace Mechanisms, Advanced Systems Laboratory, Hyderabad, 500 058, India.

J. Vib. Acoust 128(6), 699-704 (Jul 20, 2006) (6 pages) doi:10.1115/1.2345669 History: Received May 14, 2004; Revised July 20, 2006

Circular and annular dissipative ducts are extensively used for attenuation of sound in industrial applications. In most of the cases the characteristics of lining material is considered to be locally reacting, although; it may not be true always. This is because there are not many investigations available for bulk reaction modeling of circular and annular ducts. The present paper deals with a generalized formulation of a sound wave with mean and induced flow for bulk reaction approach, which can analyze sound attenuation and phase speed in circular and annular cross-section ducts. In the absence of extensive experimental data, the present theoretical model is validated by comparing a few sets of results with some published experimental results. The theoretical results are presented for various parameters of duct and lining material. More emphasis has been given to the effect of the air gap between the lining and rigid wall on the rate of attenuation and phase speed. It has been demonstrated through various sets of results that the air gap between the lining and rigid wall has a great effect on the overall performance of dissipative ducts. The present model can be used to analyze the sound field in air conditioning ducts and other similar applications.

FIGURES IN THIS ARTICLE
<>
Copyright © 2006 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

Circular duct with annular air gap between the lining and the rigid wall

Grahic Jump Location
Figure 2

Rate of attenuation for circular duct with 2a=0.038m, 2c=0.076m, L=0.325m, and Ar=0. Thicker lines (엯, ▴, and ●) are experimental findings of Cummings and Chang (see Ref. 5) and thinner solid lines (—) are corresponding theoretical findings from present analysis

Grahic Jump Location
Figure 3

Effect of mean flow and induced flow on rate of attenuation for circular duct with 2a=0.038m, 2c=0.076m, and Ar=0

Grahic Jump Location
Figure 4

Effect of thickness ratio of air gap to the liner on rate of attenuation for circular duct with a=0.10m, c=0.12m, and M=0

Grahic Jump Location
Figure 5

Effect of clear flow area on rate of attenuation for circular duct with Ar=0 and M=0

Grahic Jump Location
Figure 6

Effect of mean flow on rate of attenuation for circular duct with a=0.10m, c=0.12m, and Ar=0

Grahic Jump Location
Figure 7

Effect of mean flow on phase speed for circular duct with a=0.10m, c=0.12m, and Ar=0

Grahic Jump Location
Figure 8

Effect of mean flow on rate of attenuation for annular circular duct with a=0.10m, c=0.12m, and Ar=0.20

Grahic Jump Location
Figure 9

Effect of mean flow on phase speed for annular circular duct with a=0.10m, c=0.12m, and Ar=0.20

Grahic Jump Location
Figure 10

Effect of flow resistivity on rate of attenuation for circular duct with a=0.10m, c=0.12m, M=0, and Ar=0

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In