An experimental study of the acoustic characteristics of perforated pipe in terms of wavenumber and porosity

• Published in: Journal of sound and vibration Vol. 183; no. 1; pp. 115 - 127
• Main Authors: Kim, Y.-H., Yoon, D.-B.
• Format: Journal Article
• Language: English
• Published: London Elsevier Ltd 25.05.1995; Elsevier
• Subjects: Acoustics; Exact sciences and technology; Fundamental areas of phenomenology (including applications); Physics; Structural acoustics and vibration; Acoustic properties; Porosity; Experimental study; Perforation; Pipes; Wave number
• ISSN: 0022-460X; 1095-8568
• DOI: 10.1006/jsvi.1995.0242

The acoustic characteristics of perforated pipes have been experimentally studied in terms of transmission loss. This study includes perforated pipes having both uniform and non-uniform hole distributions along the length. The major experimental parameters are the global porosity, which is defined as the ratio of the total area of the holes in the wall of the pipe to the pipe’s cross-sectional area, and the non-dimensional wavenumber ka; kis the propagation constant and ais the distance between the perforated holes in the axial direction of the pipe. The experimental results provide information about the acoustic characteristics of perforated pipes for both the low and the high wavenumber regions. It is found that for high wave numbers that a non-uniform distribution of the holes affects only the transmission loss, and the number of holes distributed along the pipe affects the acoustic impedances of the individual holes and greatly influences the transmission loss.