Morphological evolution of three‐dimensional chemical dissolution front in fluid‐saturated porous media: a numerical simulation approach
Morphological evolution of three‐dimensional chemical dissolution front in fluid‐saturated porous media: a numerical simulation approach
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DOI：
10.1111/j.1468-8123.2008.00210.x
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发表时间：
2008-05
期刊：
影响因子：
1.7
通讯作者：
Chong-bin Zhao;B. Hobbs;A. Ord;P. Hornby;S. Peng
中科院分区：
文献类型：
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作者：
Chong-bin Zhao;B. Hobbs;A. Ord;P. Hornby;S. Peng
本文研究了流体饱和多孔介质中三维化学溶解前沿的形态演化。孔隙度，孔隙流体流动和反应性化学物质传输之间的一个完全耦合的系统被认为是描述这种现象。利用新提出的广义无因次孔隙流体压力梯度的概念，它可以用来代表溶质平流，溶质扩散，化学动力学和可溶性矿物的形状因子之间的相互作用，已建立了一个理论标准，以评估在反应传输系统中的化学溶解前沿的不稳定性的可能性。为了模拟三维流体饱和多孔介质中化学溶解前缘的演化，提出了一种有限差分法和有限元法相结合的数值方法。由于该问题属于复杂系统科学问题，在三维均质区域的初始孔隙度中加入一个随机产生的孔隙度扰动，以触发平面化学溶解前沿在流体饱和多孔介质中传播时的不稳定性。为了检验所提出的数值方法的正确性和准确性，构造了一个三维基准问题，并推导出了相关的解析解。这使得使用所提出的数值模拟的三维化学溶解前从一个稳定的，平面的状态到一个不稳定的，指状状态的形态演变的程序。相关的数值结果表明，所提出的数值方法是有用的，并能够模拟的三维化学溶解前沿的流体饱和多孔介质中的形态不稳定性。
This paper is concerned with the morphological evolution of three-dimensional chemical dissolution fronts that occur in fluid-saturated porous media. A fully coupled system between porosity, pore-fluid flow and reactive chemical species transport is considered to describe this phenomenon. Using the newly presented concept of the generalized dimensionless pore fluid pressure-gradient, which can be used to represent the interaction between solute advection, solute diffusion, chemical kinetics and the shape factor of the soluble mineral, a theoretical criterion has been established to assess the likelihood of instability at a chemical dissolution front in the reactive transport system. To simulate the chemical dissolution front evolution in a three-dimensional fluid-saturated porous medium, a numerical procedure combining both the finite difference method and the finite element method has been proposed. As the problem belongs to a complex system science problem, a small randomly generated perturbation of porosity is added to the initial porosity of a three-dimensional homogeneous domain to trigger instability of a planar chemical dissolution front during its propagation within the fluid-saturated porous medium. To test the correctness and accuracy of the proposed numerical procedure, a three-dimensional benchmark problem has been constructed and the related analytical solution has been derived. This enables using the proposed numerical procedure for simulating the morphological evolution of a three-dimensional chemical dissolution front from a stable, planar state into an unstable, fingering state. The related numerical results demonstrate that the proposed numerical procedure is useful for, and capable of, simulating the morphological instability of a three-dimensional chemical dissolution front within a fluid-saturated porous medium.