The Effect of Length on the Acoustic Attenuation Performance of Concentric Expansion Chambers: An Analytical, Computational, and Experimental Investigation The University of Michigan

Format:

Conference/Event

Author/Creator:

Selamet, A., author.

Conference Name:

International Congress & Exposition (1995-02-27 : Detroit, Michigan, United States)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 1995

Summary:

Expansion chambers are widely used in the breathing systems of engines due to their desirable broadband noise attenuation characteristics. Following an earlier analytical and computational work of Sahasrabudhe and others (1992), the present study investigates the effect of the length on the acoustic attenuation performance of concentric expansion chambers. Three approaches are employed to determine the transmission loss: (1) a two-dimensional, axisymmetric analytical solution; (2) a three-dimensional computational solution based on the boundary element method; and (3) experiments on an extended impedance tube setup with nine expansion chambers fabricated with fixed inlet and outlet ducts, fixed chamber diameters, and varying chamber length to diameter ratios from to 3.53. The results from all three approaches are shown to agree well. The effect of multi-dimensional propagation is discussed in comparison with the classical treatment for the breakdown of planar waves. The study also provides a simple relation for the number of repeating attenuation domes prior to the domination of higher order modes in terms of the l/d ratio of the expansion chamber

Notes:

Vendor supplied data

Publisher Number:

950544

Access Restriction:

Restricted for use by site license