SOUND ABSORBING SYSTEMS MADE OF WOOD CROSS SECTIONS PAIRED WITH VOID CAVITIES - A FIRST INVESTIGATION

Authors

  • Francesco Negro DISAFA - Department of Agricultural, Forest and Food Sciences University of Torino
  • Corrado Cremonini DISAFA - Department of Agricultural, Forest and Food Sciences University of Torino
  • Marco Fringuellino SAE Institute, Milano
  • Fabio Meloni DISAFA - Department of Agricultural, Forest and Food Sciences University of Torino
  • Stefano Prina DISAFA - Department of Agricultural, Forest and Food Sciences University of Torino
  • Roberto Zanuttini DISAFA - Department of Agricultural, Forest and Food Sciences University of Torino

Keywords:

Helmholtz resonance, poplar wood, porous absorbers, sound absorption, wood cross section, wood porosity

Abstract

This study investigates the possibility of exploiting the porous structure of wood for absorbing sound. With this aim, the following system is proposed: 1) the cross section of wood should be exposed to sound waves so that these can activate the vibration of air inside the wood pores; 2) the cross section should be cut to have small thickness to realize a thorough open cell absorber; 3) a void cavity should be left on the back to activate the absorption effect. This setup has been conceived to absorb sound by Helmoltz resonance. To preliminary assess the effectiveness of the system, cross sections of poplar wood were cut 1 mm thick and paired with rear void cavities 15, 30 and 50 mm thick. The normal sound absorption coefficient α was determined through the impedance tube method. Multiple absorption peaks and several α values higher than 0.6-0.7 (αmax=0.99) were measured in the medium-low frequency range. Building on these results, further studies are envisaged to model the acoustic behavior of the system and to set the technical aspects relevant to its feasibility in practice.

Author Biographies

Francesco Negro, DISAFA - Department of Agricultural, Forest and Food Sciences University of Torino

Research assistant at DISAFA, University of Torino, Italy

Corrado Cremonini, DISAFA - Department of Agricultural, Forest and Food Sciences University of Torino

Research assistant at DISAFA, Univeristy of Torino, Italy

Marco Fringuellino, SAE Institute, Milano

Lecturer at SAE Institute, Milano, Italy

Fabio Meloni, DISAFA - Department of Agricultural, Forest and Food Sciences University of Torino

Research technician at DISAFA, University of Torino, Italy

Stefano Prina, DISAFA - Department of Agricultural, Forest and Food Sciences University of Torino

Master's Degree at DISAFA, University of Torino, Italy

Roberto Zanuttini, DISAFA - Department of Agricultural, Forest and Food Sciences University of Torino

Professor at DISAFA, University of Torino, Italy

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Published

2021-02-05

Issue

Vol. 53 No. 1 (2021)

Section

Technical Notes

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