1. Modeling acoustic properties
1.1 Definition of geometric parameters
Porosity φ is the ratio of the pore volume V
p
occupied by air, to the total volume V
t
in a homogenization ball (a volume that contains a sufficient number of pores but remains small on a macroscopic scale) :
The Ultimate Scientific and Technical Reference
This article is included in
Noise and vibration
This offer includes:
Knowledge Base
Updated and enriched with articles validated by our scientific committees
Services
A set of exclusive tools to complement the resources
Practical Path
Operational and didactic, to guarantee the acquisition of transversal skills
Doc & Quiz
Interactive articles with quizzes, for constructive reading
Modeling acoustic properties
Metrology of the acoustic properties of absorbent materials
Appendix: equivalent fluid
The "effective density" and "effective modulus of compressibility" functions of the equivalent fluid must be suitably represented by the following approximate models:
References
Standardization
French Standards Association (Afnor)
- Fiberboard – Determining surface absorption – 2: test methods for hardboard. - NF EN 382-2 - (03-1994)
- Acoustics – Materials for acoustic applications – Determination of air flow resistance. - NF EN 29053 - (08-1993)
- Thermal performance of buildings – Air permeability of...
Organizations
Laboratoire d'acoustique de l'Université du Maine http://laum.univ-lemans.fr
Centre de transfert de technologie du Mans (CTTM) http://www.cttm-lemans.com
Laboratoire de sciences de l'habitat (LASH). École nationale des travaux publics...
The Ultimate Scientific and Technical Reference
