Homogenizability conditions for multicomponent reactive transport
Homogenizability conditions for multicomponent reactive transport
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DOI：
10.1016/j.advwatres.2013.07.014
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发表时间：
2013-12-01
影响因子：
4.7
通讯作者：
Battiato, Ilenia
中科院分区：
文献类型：
--
作者：
Boso, Francesca;Battiato, Ilenia
我们考虑多孔介质中的多组分反应输运，涉及三种反应物质，其中两种经历非线性均相反应，而第三种通过非均相非线性反应沉淀在固体基体上。该过程是完全可逆的，可以用a + B C s的反应来描述。系统的行为完全由Peclet （Pe）和三个Damkohler （Da(j,) j ={1,2,3}）数控制，这些数量化了输运过程中涉及的四个关键机制，即平流、分子扩散、均相和非均相反应的相对重要性。本文利用多尺度展开将孔隙尺度方程组提升到宏观尺度，并建立了宏观局部平流-弥散-反应方程（ADREs）能够准确表征孔隙尺度过程的充分条件。这些条件表明：(i)非均相反应比均相反应具有更严格的约束，（ii）在快速反应和相对低分子扩散的情况下，平流有利于增强孔隙尺度混合。通过（Pe,Da(j)）空间的相图对这些条件进行了总结，并通过具有反应壁的平面裂缝中多组分输运的数值模拟进行了验证。我们的计算表明，在我们的分析中导出的约束在确定均匀性的充分条件和必要条件方面是稳健的。(C) 2013 Elsevier Ltd.版权所有。
We consider multicomponent reactive transport in porous media involving three reacting species, two of which undergo a nonlinear homogeneous reaction, while a third precipitates on the solid matrix through a heterogeneous nonlinear reaction. The process is fully reversible and can be described with a reaction of the kind A + B C S. The system's behavior is fully controlled by Peclet (Pe) and three Damkohler (Da(j,) j = {1, 2, 3}) numbers, which quantify the relative importance of the four key mechanisms involved in the transport process, i.e. advection, molecular diffusion, homogeneous and heterogeneous reactions. We use multiple-scale expansions to upscale the pore-scale system of equations to the macroscale, and establish sufficient conditions under which macroscopic local advection-dispersion-reaction equations (ADREs) provide an accurate representation of the pore-scale processes. These conditions reveal that (i) the heterogeneous reaction leads to more stringent constraints compared to the homogeneous reactions, and (ii) advection can favorably enhance pore-scale mixing in the presence of fast reactions and relatively low molecular diffusion. Such conditions are summarized by a phase diagram in the (Pe,Da(j))-space, and verified through numerical simulations of multicomponent transport in a planar fracture with reacting walls. Our computations suggest that the constraints derived in our analysis are robust in identifying sufficient as well as necessary conditions for homogenizability. (C) 2013 Elsevier Ltd. All rights reserved.