Abstract
A dual-continuum model can offer a practical approach to understanding first-order behaviours of poromechanically coupled multiscale systems. To close the governing equations, constitutive equations with models to calculate effective constitutive coefficients are required. Several coefficient models have been proposed within the literature. However, a holistic overview of the different modelling concepts is still missing. To address this we first compare and contrast the dominant models existing within the literature. In terms of the constitutive relations themselves, early relations were indirectly postulated that implicitly neglected the effect of the mechanical interaction arising between continuum pressures. Further, recent users of complete constitutive systems that include inter-continuum pressure coupling have explicitly neglected these couplings as a means of providing direct relations between composite and constituent properties, and to simplify coefficient models. Within the framework of micromechanics, we show heuristically that these explicit decouplings are in fact coincident with bounds on the effective parameters themselves. Depending on the formulation, these bounds correspond to end-member states of isostress or isostrain. We show the impacts of using constitutive coefficient models, decoupling assumptions and parameter bounds on poromechanical behaviours using analytical solutions for a 2D model problem. Based on the findings herein, we offer recommendations for how and when to use different coefficient modelling concepts.
Original language | English |
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Pages (from-to) | 699-730 |
Number of pages | 32 |
Journal | Transport in Porous Media |
Volume | 130 |
Issue number | 3 |
Early online date | 16 Sept 2019 |
DOIs | |
Publication status | Published - Dec 2019 |
Keywords
- Constitutive models
- Dual-continuum
- Micromechanics
- Multiscale porous media
- Poromechanics
ASJC Scopus subject areas
- Catalysis
- General Chemical Engineering