The Impact of Pore Structure Heterogeneity, Transport, and Reaction Conditions on Fluid-Fluid Reaction Rate Studied on Images of Pore Space
The Impact of Pore Structure Heterogeneity, Transport, and Reaction Conditions on Fluid-Fluid Reaction Rate Studied on Images of Pore Space
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DOI：
10.1007/s11242-016-0758-z
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发表时间：
2016-11-01
影响因子：
2.7
通讯作者：
Bijeljic, B.
中科院分区：
文献类型：
--
作者：
Alhashmi, Z.;Blunt, M. J.;Bijeljic, B.
我们使用孔隙尺度流体-流体反应性传输模型进行直接数值模拟（Alhashmi等人，J Contam Hydrol 179：171-181，2015）。DOI：10.1016/J.Jconhyd.2015.06.004）以研究孔结构不均匀性对不同多孔介质中有效反应速率的影响。我们模拟流动，运输和反应在三个孔隙尺度的图像：一个beadpack，Bentheimer砂岩，和Doddington砂岩的一系列运输和反应条件。我们计算的反应速率，速度分布，和分散系数比较它们与非反应性运输的结果。反应速率是混合和扩散量的微妙组合，不能从非反应性分散系数预测。我们演示了流场的非均匀性如何影响有效反应速率。取决于固有流场非均匀性特征和流速，反应可以：（a）出现在既有滞留粒子又有注入粒子的区域（对于低P、低Clet数和均匀流场），（B）优先发生在羽流的后缘（c）在慢速移动区（对于高P、高Clet数和非均匀流场）中不受欢迎。
We perform direct numerical simulation using a pore-scale fluid-fluid reactive transport model (Alhashmi et al. in J Contam Hydrol 179:171-181, 2015. doi:10.1016/j.jconhyd.2015.06.004) to investigate the impact of pore structure heterogeneity on the effective reaction rate in different porous media. We simulate flow, transport, and reaction in three pore-scale images: a beadpack, Bentheimer sandstone, and Doddington sandstone for a range of transport and reaction conditions. We compute the reaction rate, velocity distributions, and dispersion coefficient comparing them with the results for non-reactive transport. The rate of reaction is a subtle combination of the amount of mixing and spreading that cannot be predicted from the non-reactive dispersion coefficient. We demonstrate how the flow field heterogeneity affects the effective reaction rate. Dependent on the intrinsic flow field heterogeneity characteristic and the flow rate, reaction may: (a) occur throughout the zones where both resident and injected particles exist (for low P,clet number and a homogeneous flow field), (b) preferentially occur at the trailing edge of the plume (for high P,clet number and a homogeneous flow field), or (c) be disfavored in slow-moving zones (for high P,clet number and a heterogeneous flow field).