Influence of diffusion and sorption on sound propagation in multiscale porous materials

Venegas, R; Boutin, C; Umnova, O

Abstract

This paper investigates sound propagation in multiscale sorptive porous materials saturated with a pure gas. An example of this type of materials is a packing of porous grains where a mesoscopic, microscopic, and nanoscopic scale can be identified. These scales are associated with the grain size, and the pores inside the grains of micrometre and nanometre sizes, respectively. Considering that the inner-grain and inter-granular viscous permeabilities are highly contrasted, the macroscopic description of sound propagation through the material is established by upscaling a local mesoscopic description using the two-scale asymptotic method of homogenisation for periodic media. The local mesoscopic description is given by i) an homogenised description of the inner-grain physics that accounts for fluid flow and heat conduction
in the micropores, inner-grain interscale mass difussion, and sorption occurring on the walls of the nanopores, ii) the equations describing fluid flow and heat conduction in
the mesoscopic fluid network, and iii) the conditions of continuity of mass flux and pressure, and negligible temperature variations on the pore boundaries. It is concluded that the effective compressibility becomes significantly affected by sorption and interscale
pressure and mass diffusion processes. This leads to a decrease in sound speed and an increase in sound attenuation, particularly around the characteristic frequencies associated to the diffusion processes.

Citation

Venegas, R., Boutin, C., & Umnova, O. (2017, July). Influence of diffusion and sorption on sound propagation in multiscale porous materials. Presented at 6th Biot Conference on Poromechanics, Paris, France

• Presentation Conference Type: Other
• Conference Name: 6th Biot Conference on Poromechanics
• Conference Location: Paris, France
• Start Date: Jul 9, 2017
• End Date: Jul 13, 2017
• Publication Date: Jul 6, 2017
• Deposit Date: Oct 26, 2017
• Publicly Available Date: Oct 26, 2017
• Book Title: Poromechanics VI
• DOI: https://doi.org/10.1061/9780784480779.217
• Publisher URL: http://dx.doi.org/10.1061/9780784480779.217
• Related Public URLs: http://ascelibrary.org/doi/book/10.1061/9780784480779
• Additional Information: Additional Information : Published version of record available via ASCE Library.; Event Type : Conference