Design charts and experiment for sound attenuation in a circular lined

Author

Yunoki, Ken´ichi ; Ito, Shiro ; Ando, Yoichi

Author_Institution

Fac. of Eng., Kagoshima Univ., Japan

fYear

1999

fDate

36373

Firstpage

885

Lastpage

888

Abstract

In this paper, sound attenuation characteristics of a circular lined duct are studied generally by varying the value of a complex reflection coefficient at its inner surface. In this study, at first, eigenvalue equations are solved by using a complex reflection coefficient and and frequency parameter. Next, the sound attenuations between two cross sections of the duct are shown,after sound intensities are calculated. On the other hand,the above theoretical results are confirmed by the experiments. We measured the complex reflection coefficients and the sound attenuation of two kinds of lined ducts. The experimental results about sound attenuation approximately coincided with theoretical ones

Keywords

acoustic wave absorption; acoustic wave reflection; acoustic wave transmission; eigenvalues and eigenfunctions; noise abatement; circular lined duct; complex reflection coefficient; eigenvalue equations; sound attenuation; Acoustic propagation; Acoustic reflection; Attenuation measurement; Ducts; Educational institutions; Eigenvalues and eigenfunctions; Equations; Frequency; Indium tin oxide; Microphones;

fLanguage

English

Publisher

ieee

Conference_Titel

SICE Annual, 1999. 38th Annual Conference Proceedings of the

Conference_Location

Morioka

Print_ISBN

4-907764-13-8

Type

conf

DOI

10.1109/SICE.1999.788595

Filename

788595