• Français
    • English
  • Français 
    • Français
    • English
  • Login
View Document 
  •   Savoirs UdeS Home
  • Génie
  • Génie – Thèses
  • View Document
  •   Savoirs UdeS Home
  • Génie
  • Génie – Thèses
  • View Document
JavaScript is disabled for your browser. Some features of this site may not work without it.

Browse

All of Savoirs UdeSDomains & CollectionsBy Issue DateAuthorsTitlesSubjectsDirectorsThis CollectionBy Issue DateAuthorsTitlesSubjectsDirectors

My Account

Login

Statistics

View Usage Statistics

Microstructure et macro-comportement acoustique : approche par reconstruction d'une cellule élémentaire représentative

Thumbnail
View/Open
NR30971.pdf (11.70Mb)
Publication date
2006
Author(s)
Perrot, Camille
Subject
Dynamic thermal and viscous permeabilities
 
Brownian motion
 
Microtomography
 
Reconstruction method
 
Open-cell foams
 
Porous media
 
Acoustics
 
Microstructure
Show full document record
Abstract
The fundamental issue of determining acoustic properties of porous media from their local geometry is examined in this PhD dissertation thesis, thanks to a sample of open-cell aluminum foam analyzed by axial computed microtomography. Various geometric properties are measured to characterize the experimental sample at the cell size level. This is done in order to reconstruct a porous medium by means of idealized three- and two- dimensional unit-cells.The frequency dependant thermal and velocity fields governing the propagation and dissipation of acoustic waves through rigid porous media are computed by Brownian motion simulation and the finite element method, respectively. Macroscopic behavior is derived by spatial averaging of the local fields. Our results are compared to experimental data obtained from impedance tube measurements. Firstly, this approach leads to the identification of the macroscopic parameters involved in Pride and Lafarge semiphenomenological models. Secondly, it yields a direct access to thermal and viscous dynamic permeabilities. However, the bi-dimensional model underestimates the static viscous permeability as well as the viscous characteristic length; what thus require a three-dimensional implementation.
URI
http://savoirs.usherbrooke.ca/handle/11143/1799
Collection
  • Génie – Thèses [815]

DSpace software [version 5.4 XMLUI], copyright © 2002-2015  DuraSpace
Contact Us | Send Feedback
 

 


DSpace software [version 5.4 XMLUI], copyright © 2002-2015  DuraSpace
Contact Us | Send Feedback