Homogenization based two-scale modelling of ionic transport in fluid saturated deformable porous media

Abstract

The paper deals with the homogenization of deformable porous media saturated by twocomponent electrolytes. The model relevant to the microscopic scale describes steady states of the medium while reflecting essential physical phenomena, namely electrochemical interactions in a dilute Newtonian solvent under assumptions of a small external electrostatic field and slow flow. The homogenization is applied to a linearized micromodel, whereby the thermodynamic equilibrium represents the reference state. Due to the dimensional analysis, scaling of the viscosity and electric permitivity is introduced, so that the limit model retains the characteristic length associated with the pore size and the electric double layer thickness. The homogenized model consists of two weakly coupled parts: the flow of the electrolyte can be solved in terms of a global pressure and streaming potentials of the two ions, independently of then the solid phase deformations which is computed afterwards for the fluid stress acting on pore walls. The two-scale model has been implemented in the Sfepy finite element software. The numerical results show dependence of the homogenized coefficients on the microstructure porosity. By virtue of the corrector result of the homogenization, microscopic responses in a local representative cell can be reconstructed from the macroscopic solutions.

Fast Evaluation of Finite Element Weak Forms Using Python Tensor Contraction Packages

“…The transpiler and einsum expression based weak form implementations are available in SfePy from version 2021.1, allowing a rapid prototyping of multi-physical finite element models and subsequent calculations in various fields such as biomechanics [30] or solid state physics [22]. All data used in preparation of this paper are available online [8].…”

Determination of geometrical parameters of the microstructure of a porous medium: Application to cementitious materials

“…diffusion-reaction problems [42], alkaline -silica reaction (ASR) [43], thermal conduction [44,45], modeling of calcium leaching [46], and the transfers of chloride ions taking into account ionic electrocapillary interactions with the solid matrix [37,47,48,49], etc. Finally, let us cite also recent works using homogenization by two scales convergence methods [50,51] The aim of this paper is to develop a pertinent approach to evaluate the tortuosity and constrictivity of porous media, mainly cementitious materials, by asymptotic periodic homogenization from transport equations written at the local scale for each phase of the cementitious material.…”