A granular thermodynamic framework-based coupled multiphase-substance flow model considering temperature driving effect

Based on the energy dissipation caused by consolidation deformation of the porous media under external force and migration of the internal suspended substances, a coupled multiphase-substance flow (CMF) model was established. This model introduced the new concepts, such as particle temperature and particle entropy, to describe energy dissipation at meso-level. This model used a potential energy density function and migration coefficients to establish the corresponding connection between the dissipative force and dissipative flow. This viewpoint unifies the deformation, seepage, and suspended substance migration of geotechnical materials under the framework of granular thermodynamics. It can reflect the evolution of effective stress in the solid matrix of multi-components in a particle-reorganized state, and considers the temperature driving effect. The proposed CMF model is validated using the experimental results under coupled migration of heavy metal ions (HMs) and suspended particles (SPs). The calculation results demonstrated that the CMF model can describe the flow process under the conditions of arbitrary changes in different suspended substance types, injection concentrations, and injection velocities.