EXPERIMENTAL INVESTIGATION AND NUMERICAL SIMULATION OF THE ACOUSTIC WAVES PROPAGATION IN A STANDING WAVE TUBE. TESTING WITH A SAMPLE OF ROCKWOOL

Abstract

[EN] Characterization of sound-absorbing materials is one of the investigation fields that is acquiring most interest in the last few years. As a consequence, there is an increase in investigators who are trying to obtain mathematical models to predict the acoustical behavior of the materials, as well as those who are looking for new materials to improve the acoustic isolation and acoustic conditioning. There are lots of applications, such as mufflers used in engines, in which it is of great interest to know the velocity of sound waves and the pressure distribution inside ducts. In this paper, the numerical simulation technique based on the finite element method is applied to study the propagation of the plane acoustic waves inside a standing wave tube by means of the application of a harmonic analysis, studying the distribution of pressures in an established frequency range. ANSYS software has been used to compare the numerical results with the theoretical ones. Then, comparing the numerical results with the experimental ones, the validity of the experimental method is evaluated. The experimental method follows the Standard ISO 10534-2 that is used for the determination of the absorption coefficient and acoustic impedance in porous and fibrous materials. © 2011, Society for Experimental Mechanics.