Abstract
Fluid flow in a dual permeable medium (DPM) is essential in solute transport in mining and aquifer studies. In this paper, water flushing into a contaminated DPM containing fine-grained lenses with different geometries was investigated with the Lattice Boltzmann Method (LBM). The LBM model used in this study was D2Q9 with a relaxation time of 1, a cohesion value of 3 for a fluid density of 1 (mu.Lu-3). The saturated fluid in the DPM was a contaminant that usually stays in low permeable lenses and after flushing, it is leaked into the porous medium by a second fluid (water). This phenomenon is predominant when the displacing fluid has a lower concentration than the contaminated fluid. Diffusion and advection are the main mechanisms that control fluid flow in the porous medium. The results of the simulations showed: (1) advection controlled solute transport through the flushing phase, and back-diffusion occurred after the change in phase; (2) the lenses’ geometry influenced the fluid flow pattern and the remediation process. As a result, aquifer remediation strategies based on the lenses’ geometry and their permeability can help us select the appropriate environmental protection.
Highlights
Fluid flow and its interaction with the solid surface of a porous material with complex structures has broad industrial applications, such as in oil and gas recovery, open and underground mines, and radioactive waste deposits (Kantzas et al, 2015; Medunić et al, 2018; Mohammadi et al, 2019; Veinović et al, 2020)
Aquifer restoration time in a real site is strongly dependent on contaminant type, fluid properties, and many other parameters, such as mineralogy and geometry of Corresponding author: Faramarz Doulati Ardejani fdoulati@ut.ac.ir grains, pore size distribution, open and closed fracture, and so forth
The Lattice Boltzmann Method (LBM) was derived from the lattice-gas automata (LGA) as a mesoscale method (Pulvirenti and Tirozzi, 1973)
Summary
Fluid flow and its interaction with the solid surface of a porous material with complex structures has broad industrial applications, such as in oil and gas recovery, open and underground mines, and radioactive waste deposits (Kantzas et al, 2015; Medunić et al, 2018; Mohammadi et al, 2019; Veinović et al, 2020). The first class is the simulation by considering macro variables and solving continuity equation by finite difference, finite element, and finite volume methods. These methods are based on the discretization of Navier-Stokes equations assuming a continuous flow medium (Mohamad, 2019). The LBM is one of these techniques for simulation of fluid flow in mesoscale (McNamara and Zanetti, 1988). The main advantages of using the LBM are: (1) high speed performance; (2) parallel computation; (3) simple implementation without solving differential equations; (4) pore-scale flow behaviour in complex structures and boundary conditions; and (5) multi-phase and incompressible fluid flow simulation. Some relevant research for the current study regarding the LBM showed its capability to determine permeability in a rough fracture (Eker and Akin, 2006), to study the groundwater flow and solute transport in a karstic porous medium (Sukop et al, 2008), to evaluate the permeability and non-Darcy flow in South Florida limestone (Sukop et al, 2013), to predict the permeability of real and synthetic porous media (Boek and Venturoli, 2010), to study the effects of stress on relative permeability (Huang et al, 2021), and to analyse the effect of heterogeneous complex porous media on fluid flow pattern (Shiri et al, 2018; Shiri and Hassani, 2021; Shiri and Shiri, 2021)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
