On the Influence of Permeability and Young's Modulus on the Dehydration of a Strongly Shrinkable Two-Phase Porous Medium: A Model Sensibility Analysis and the Development of a Contact Mechanics Measurement Setup

A model that describes the mass transfer in a two-phase shrinkable porous media by using a classic Darcy law for the fluid relative to solid transfer has been recently developed by Cáceres et al.^[ 1-2 Cáceres , G. ; Bruneau , D. ; Jomaa , W. Two-phase shrinking porous media drying: A modeling approach including liquid pressure gradients effects . Drying Technology 2007 , 25 , 1927 – 1934 . Cáceres , G. Modeling the drying of a saturated shrinkable porous medium: Taking into account the liquid pressure. Ph.D. Thesis, University of Bordeaux, France, 2006 (in French).   ^] This model describes the coupling between the fluid pressure and the solid structure deformation tensor by using the Terzaghi stress tensor decomposition for the media and elastic constitutive law for the solid structure.^{[ 3} Terzaghi , K. Theoretical Soil Mechanics ; John Wiley & Sons : New York , 1943 .[Crossref] , [Google Scholar] ^]

The aim of this article is to point out the sensitivity of this model relative to the two main physical parameters that govern the coupled mass transfer and stress level in a strongly shrinkable porous medium, namely, permeability and the Young's modulus. An experimental setup that makes possible the simultaneous measurement of those two parameters as well as the Poisson ratio is developed in agreement with the recent theoretical suggestions of Lin et al. The experimental evolution of these quantities versus the moisture content is discussed for an agar gel.