Proceedings of the Korean Society for Noise and Vibration Engineering Conference (한국소음진동공학회:학술대회논문집)
- 2001.11b
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- Pages.1347-1352
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- 2001
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- 1598-2548(pISSN)
Acoustical Properties of Polyester Sound Absorbing Materials
폴리에스테르 흡음재의 음향특성
Abstract
In this study, the acoustic properties of polyester sound absorbing materials with three different bulk densities were investigated by calculating and measuring the acoustic parameters in terms of characteristic impedance, propagation constant, and absorption coefficient. For the calculations, Delany and Bazley's empirical equation was used together with the experimentally obtained specific flow resistivities under steady flow conditions. For the experimental measurements, the well-known two-thickness method was accessed. The experimentally measured values of characteristic impedance and propagation constant were generally agreed well with the corresponding calculated values. Based on the comparisons between the calculations and measurements, it was found that the magnitude of the absorption coefficient was closely related to the characteristic impedance and the real part of the propagation constant. Especially, the maximum magnitude of the absorption coefficient was depended upon the imaginary part of the propagation constant indicating the phase change of the propagation constant.
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