Study on Attenuation of Acoustic Waves Propagating through Thin Tubes

Abstract

This paper describes the attenuation of sound in the pipe. The complex density, which represents the sum of the inertial force of the fluid and the viscous damping, is used to attenuate the sound in the tube. For this complex density, the complex density that represents the attenuation of sound is derived assuming the Poiseuille flow, which is generally a steady flow. However, focusing on the fact that the sway of air when sound propagates is not a steady flow but a non-steady flow, the purpose of this study is to find the complex density by a new method. In addition, the validity of the complex density will be examined by comparing the specific acoustic impedance obtained in the experiment with the value of the specific acoustic impedance obtained from the obtained complex density.