Introduction
Mixture coupling theory is a theoretical framework used to model the behavior of multi-phase fluids in deformable porous media. It is based on the principle that the different phases of the fluid interact with each other through interfacial forces, resulting in mass, momentum, and energy transfer between the phases.
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In mixture coupling theory, each phase is considered as a separate entity with its own set of properties, such as density, velocity, and temperature. However, unlike mixture theory, mixture coupling theory accounts for the interaction between the phases and the interfacial forces that exist at the boundaries between the phases. This approach is more detailed than mixture theory, as it takes into account the dynamics of the interfaces between the different phases.
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Mixture coupling theory is often used in situations where the phases are not in equilibrium, such as in the case of non-equilibrium phase transitions or in the presence of surface tension. It is also useful in situations where the different phases have significantly different properties, such as in the case of immiscible fluids.
The advantage of mixture coupling theory over mixture theory is that it provides a more accurate and detailed description of the fluid behavior. By taking into account the interaction between the different phases and the interfacial forces, mixture coupling theory can capture the dynamics of the system more accurately. This is particularly important in situations where the system is complex and the phases are not in equilibrium.
However, mixture coupling theory is more computationally intensive and requires more resources than mixture theory. It is also more challenging to implement, as it requires the use of advanced numerical methods to solve the equations that govern the behavior of the system.
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We are currently leading research in the development of mixture coupling theory, with applications in many cross-disciplinary fields.
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Related research can be divided into：
​Part 1. New coupled Thermo-Hydro-Mechanical-Chemical formulations with consideration of swelling
Part 2. Multi-physics modelling of groundwater contamination in shale gas reservoirs
Part 1. New coupled Thermo-Hydro-Mechanical-Chemical formulations with consideration of swelling and dissolution
Dr Yue Ma
The Mixture-Coupling Theory (MCT) is extended to develop a new Thermo-Hydro-Mechanical-Chemical model by including swelling (e.g., hydration) and dissolution in soils/rocks, with the engineering application focusing on nuclear waste disposal. The new theory is based on non-equilibrium thermodynamics and continuum mechanics. Both saturated/unsaturated HM, HMC, and THMC models are developed with consideration of swelling and dissolution is derived. The research can help achieve a deeper understanding of the rock/clay behaviour of the multi-barrier system and provides a more realistic prediction for nuclear waste disposal safety assessment.
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Related publications
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Ma, Y., Ge, S., Yang, H., Chen, X.H. Coupled thermo-hydro-mechanical-chemical processes with reactive dissolution by non-equilibrium thermodynamics[J]. Journal of the Mechanics and Physics of Solids, 2022, 169: 105065.
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Ma, Y., Chen, X.H *., Hosking L J., Yu, H.S., Thomas, H.R., 2022. THMC constitutive model for membrane geomaterials based on Mixture Coupling Theory. International Journal of Engineering Science, 2022, 171: 103605
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Ma, Y., Chen, X.H*., Hosking, L.J., Yu, H.S., Thomas, H.R. and Norris, S., 2021. The influence of coupled physical swelling and chemical reactions on deformable geomaterials. International Journal for Numerical and Analytical Methods in Geomechanics, 45(1), pp.64-82
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Ma, Y., Chen, X.H.* and Yu, H.S., 2020. An extension of Biot's theory with molecular influence based on mixture coupling theory: Mathematical model. International Journal of Solids and Structures, 191, pp.76-86.
Part 2. Multi-physics modelling of groundwater contamination in shale gas reservoirs
Mr Kai Wang, PhD Candidate
Based on the mixed coupling theory, a multi-field coupling mathematical model of underground migration of shale gas fracturing pollutants is established. The multi-field coupling numerical calculation model of underground migration of shale gas fracturing pollutants is constructed. The migration process of target pollutants under the action of complex multi-physical fields during fracturing is quantified, and the migration range of pollutants and the impact of groundwater environment are predicted.
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Related publications
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Wang Kai, Ma Yue, Howlett Paul R, Ding Aizhong, and Chen Xiao-Hui. New Unsaturated Dynamic Porosity Hydromechanical Coupled Model and Experimental Validation[J]. International Journal of Geomechanics, 2022, 22(10): 04022171.
