Innovative THMC Modeling for Environmental Remediation

Abstract:

To simulate comprehensively coupled processes of thermal-hydrology-mechanics-chemistry (THMC), governing equations are needed for transport of an arbitrary number of chemical species, hydrological flow of an arbitrary number of fluid and solid phases, displacement, and temperature. These governing equations are supplemented with Darcy's law for fluid phase velocities, constraints on species concentrations, equation of states, and constitutive laws. Conventionally, these equations are implicitly coupled via the calculations of secondary variables based on primary variables. The mechanisms of coupling are obscured. In this paper, an innovation THMC modeling is proposed, that explicitly couples governing equations for primary variables. The coupling is accomplished via the storage coefficients, effective transporting velocities, and equivalent conduction-dispersion-diffusion coefficient tensors, one set each for every primary variable. It is believed that this THMC model could serve as a prototype for simulating many types of environmental remediation. Examples will demonstrate the intuition and superiority of this THMC modeling system. Case studies illustrate how to apply this model for environmental remediation as well.