Measurement of the acoustical impedance of a black box at low frequencies using a shorter impedance tube

Kathuriya, ML and Munjal, ML (1977) Measurement of the acoustical impedance of a black box at low frequencies using a shorter impedance tube. In: Journal of the Acoustical Society of America, 62 (3). pp. 751-754.

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Abstract

For the experimental evaluation of the acoustical impedance of a termination by the impedance-tube method at low frequencies, the length of the impedance tube is a problem. In the present paper, the method of exact analysis of standing waves developed by the authors for the stationary medium as well as for mean flow, has been extended for measurement of the acoustical impedance of a termination at low frequencies. The values of the tube attenuation factor and the wave number at the low frequency of interest are established from the experiment conducted, with the given impedance tube, at a higher frequency. Then, exciting the tube at the desired low frequency it is sufficient to measure sound pressure at three differenct locations (not necessarily the minima) in order to evaluate reflection coefficient and hence the impedance of the termination at that frequency.

Item Type:	Journal Article
Publication:	Journal of the Acoustical Society of America
Publisher:	American Institute of Physics
Additional Information:	Copyright of this article belongs to American Institute of Physics.
Department/Centre:	Division of Mechanical Sciences > Mechanical Engineering
Date Deposited:	21 Jan 2010 06:34
Last Modified:	19 Sep 2010 05:50
URI:	http://eprints.iisc.ac.in/id/eprint/24399

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