Effects of mechanical dispersion on the morphological evolution of a chemical dissolution front in a fluid-saturated porous medium

A porosity-gradient replacement approach for computational simulation of chemical-dissolution front propagation in fluid-saturated porous media including pore-fluid compressibility

“…To improve the solution convergence, a porositygradient replacement approach, in which the term involving porosity-gradient computation is replaced by a new term consisting of pore-fluid density-gradient and pressure-gradient computation, is proposed in this study. This is the main difference between this study and the previous studies [1,3,4,12,13,22]. In addition, the proposed porosity-gradient replacement approach is not only useful for the computational simulation of the chemical-dissolution-front propagation problem associated with the ore body formation and mineralization in the upper crust of the Earth, but also applicable to the computational simulation of the chemicaldissolution-front propagation problem associated with the leaching minerals from cementitious materials [7,10], because the physicochemical mechanism and mathematical models of these two kinds of problems are very similar.…”

“…Under the stimulus of further understanding the physical and chemical processes that control ore body formation and mineralization in the upper crust of the Earth, a considerable amount of work has been carried out, in the recent years, for solving reactive mass transport problems in fluid-saturated porous media [4,9,11,14,16,17,19,[21][22][23][24]. In particular; Zhao et al [22] have established a theoretical framework for the chemical dissolution front instability in a fluidsaturated porous medium when the pore-fluid is incompressible.…”

“…Otherwise, it is unstable; (3) the chemical dissolution front has a step shape when the mineral dissolution ratio approaches zero; (4) the particle shape, solute dispersion and mineral dissolution ratio can have significant effects on the stability of chemical dissolution fronts in supercritical chemical dissolution systems. Nevertheless, to the best knowledge of the authors, the pore-fluid compressibility has been often neglected for the computational simulation of chemical-dissolution-front propagation problems in fluid-saturated porous media in the previous studies [1,3,4,12,13,22], so that it becomes the main purpose of this investigation.…”

Computational simulation for the morphological evolution of nonaqueous phase liquid dissolution fronts in two-dimensional fluid-saturated porous media

“…This is true when the longitudinal dispersivity is equal to the transversal dispersivity in the fluid-saturated porous medium. It is a good approximation when the perturbed aqueous phase (secondary) flow in the vertical direction perpendicular to the injected aqueous phase (primary) flow direction is much slower than the injected aqueous phase (primary) flow in the horizontal direction within a rectangular domain [6,39]. Nevertheless, for NAPL dissolution problems involving irregular domains, the injected aqueous phase (primary) flow may have the same order of magnitude in both the horizontal and vertical directions, so that off-diagonal terms in the dispersion tensor need to be considered.…”

Theoretical Analyses of the Effects of Solute Dispersion on Chemical-Dissolution Front Instability in Fluid-Saturated Porous Media

“…The instability of a chemical-dissolution front is an important scientific problem associated with reactive transport processes in fluid-saturated porous media (Chadam et al 1986(Chadam et al , 1988Ortoleva et al 1987;Imhoff and Miller 1996;Renard et al 1998;Imhoff et al 2003;Chen and Liu 2002;Chen et al 2009;Zhao et al 2008aZhao et al ,b, 2009a. This problem has a broad scientific and engineering background in the fields of geoscience, mining engineering, petroleum engineering, geoenviromental engineering and so forth.…”