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Characterisation material physical properties of porous materials
Engineering and Construction
Pages 12 (3012 words)
Characterisation of Material Physical Properties of Porous Materials: A Review 1 Background (Introduction) Porous materials with acoustical properties have important applications as noise absorbing materials in various industries. The characterization of the material properties of porous materials is an important criterion for the prediction of their acoustical and sound absorbing behaviour…
According to this theory, three different kinds of waves propagate within the porous material. One is the compression wave propagating in the fluid phase, the second is the compression wave travelling in the solid phase, and the third is the shear wave propagating in the solid phase (Pan & Jackson). The Biot model for predicting sound propagation in porous materials is based on five material properties, also called Biot parameters, of the material. These five parameters include the porosity of the material, its airflow resistivity, tortuosity, thermal characteristic length, and viscous characteristic length. The present review discusses the current methods for measuring and predicting these five Biot parameters. 2 Material Physical Properties in Biot Theory This section details the characterization of the material physical properties, i.e. the five Biot parameters, of porous materials. A review of the properties themselves along with the methods for measuring and predicting them is presented. 2.1 Porosity (?) The porosity of a material is the “relative fraction, by volume, of the air contained within the material” (Fellah et al. 2003, p. 296). ...
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