A new pore-scale model for linear and non-linear heterogeneous dissolution and precipitation
A new pore-scale model for linear and non-linear heterogeneous dissolution and precipitation
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DOI：
10.1016/j.gca.2013.09.003
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发表时间：
2014-01-01
影响因子：
5
通讯作者：
Parmigiani, Andrea
中科院分区：
文献类型：
--
作者：
Huber, Christian;Shafei, Babak;Parmigiani, Andrea
在连续介质尺度下，孔隙尺度过程对反应物在多孔介质中的输运具有很强的控制作用。因此，孔尺度数值模型可以提供一个更定量的理解之间的耦合传输和反应，并产生参数化的本构方程，引入孔尺度修正到宏观（连续）reactiontransmittingmodels.In本研究中，我们提出了一个新的孔尺度模型的反应物在多孔介质中的对流和扩散的复杂拓扑结构。该模型是基于格子玻尔兹曼方法和耦合的流体流动求解器的最佳对流扩散传输模型。内部固体-流体边界（晶粒边界）是数值域的一部分，这允许算法独立于晶粒的表面形状和取向来求解表面反应。因此，该方法非常适合于处理复杂的孔隙结构中的非均相反应。我们提出了单和多物种反应输运模型的应用。在第一个应用程序中，我们研究了渗透率的变化与给定的孔隙度变化过程中的溶解和沉淀使用线性反应动力学的多孔介质。我们表明，对于一个给定的多孔介质，孔隙度和渗透率的变化之间的相关性取决于运输制度（对流扩散运输的比率）和反应速率。最后，我们进行了多物种反应性运输的模拟，重点是碳酸钙溶解/沉淀的情况下。我们的研究结果突出了pH依赖性和独立的反应速率之间的差异，在复杂的几何形状在孔尺度的非均相反应。(C)2013爱思唯尔有限公司保留所有权利。
Pore-scale processes exert a strong control on the transport of reactants in porous media at the continuum scale. As such, pore-scale numerical models can offer a more quantitative understanding of the coupling between transport and reaction and yield parameterized constitutive equations to introduce pore-scale corrections into macroscopic (continuum) reactive transport models.In the present study, we present a new pore-scale model for the advection and diffusion of reactants in porous media with complex topologies. The model is based on the lattice Boltzmann method and couples a fluid flow solver to an optimal advection-diffusion transport model. Internal solid-fluid boundaries (grain boundaries) are explicitly part of the numerical domain, which allows the algorithm to solve for surface reactions independently from the surface shape and orientation of the grains. Thus, the approach is well suited for the treatment of heterogeneous reactions in complex pore structures.We present single and multispecies reactive transport applications of the model. In the first application we study the permeability change of a porous medium associated with a given porosity change during dissolution and precipitation using linear reaction kinetics. We show that, for a given porous medium, the correlation between porosity and permeability changes depends on the transport regime (the ratio of advective to diffusive transport) and the reaction rate. Finally, we carry out simulations of multispecies reactive transport, focusing on the case of calcium carbonate dissolution/precipitation. Our results highlight the difference between pH dependent and independent reaction rates for heterogeneous reactions in complex geometries at the pore scale. (C) 2013 Elsevier Ltd. All rights reserved.