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# Acoustic Field in Ducts With Sinusoidal Area Variation

[+] Author and Article Information

Experimental Aerodynamics Division,
National Aerospace Laboratories,
Bangalore 560 017, India
e-mail: vikram_sri@yahoo.com

R. B. Kaligatla

Department of Mathematics,
Chennai 600 036, India

1Corresponding author.

Contributed by the Noise Control and Acoustics Division of ASME for publication in the JOURNAL OF VIBRATION AND ACOUSTICS. Manuscript received December 26, 2012; final manuscript received September 11, 2013; published online October 3, 2013. Assoc. Editor: Theodore Farabee.

J. Vib. Acoust 136(1), 014502 (Oct 03, 2013) (3 pages) Paper No: VIB-12-1360; doi: 10.1115/1.4025441 History: Received December 26, 2012; Revised September 11, 2013

## Abstract

The purpose of this article is to provide an analytical solution for the acoustic field in a duct with sinusoidal area variation along the length. The equation describing the acoustic field in a variable area duct is a second-order partial differential equation. It is converted into a second-order ordinary linear differential equation, whose solution is dependent on the choice of area variation. The solution for the differential equation is obtained in terms of the area and is obtained neglecting the mean flow. Therefore, it is applicable in the absence of mean flow or in cases where the effects of mean flow are insignificant.

## References

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