Derivation of an effective dispersion model for electro-osmotic flow involving free boundaries in a thin strip
Derivation of an effective dispersion model for electro-osmotic flow involving free boundaries in a thin strip
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涉及薄带自由边界的电渗流有效分散模型的推导
DOI：
10.1007/s10665-019-10024-8
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发表时间：
2019
影响因子：
1.3
通讯作者：
R. Schulz
中科院分区：
文献类型：
--
作者：
N. Ray;R. Schulz
由于弥散是溶质运移的关键参数之一，其准确的模拟对于避免对流动和运移行为的错误预测是必不可少的。在这项研究中，我们得到了新的有效色散模型，这些模型在几何演化中也是有效的。为此，我们考虑了在主要流动条件下(即，对于高Peclet数)，在可能演化的薄条带中的反应离子传输。除了压力驱动流外，电荷和感应电势(Zeta电位)还会引起电渗流。在孔隙尺度上，引入了一个耦合偏微分方程组的数学模型。如果适用，则通过层的厚度来考虑自由边界，即固定化学物种的附着层与流体之间的界面。对于该模型，应用了一种形式的限制程序，并研究了由此产生的色散效应的放大模型。在此过程中，我们强调了流体动力弥散(Taylor-Aris弥散)和电渗流产生的弥散的交叉耦合效应。此外，我们还研究了小德拜长度和大德拜长度的极限。我们的结果提高了对流动和传输过程的基本原理的理解，因为我们现在可以显式地计算弥散系数，即使在演变的几何图形中也是如此。进一步的研究肯定可以通过数值研究的方式来解决堵塞的情况。最后，突破曲线的改进预测以及混合和分离过程的简化建模是可能的。
Since dispersion is one of the key parameters in solute transport, its accurate modeling is essential to avoid wrong predictions of flow and transport behavior. In this research, we derive new effective dispersion models which are valid also in evolving geometries. To this end, we consider reactive ion transport under dominate flow conditions (i.e. for high Peclet number) in a thin, potentially evolving strip. Electric charges and the induced electric potential (the zeta potential) give rise to electro-osmotic flow in addition to pressure-driven flow. At the pore-scale a mathematical model in terms of coupled partial differential equations is introduced. If applicable, the free boundary, i.e. the interface between an attached layer of immobile chemical species and the fluid is taken into account via the thickness of the layer. To this model, a formal limiting procedure is applied and the resulting upscaled models are investigated for dispersive effects. In doing so, we emphasize the cross-coupling effects of hydrodynamic dispersion (Taylor–Aris dispersion) and dispersion created by electro-osmotic flow. Moreover, we study the limit of small and large Debye length. Our results improve the understanding of fundamentals of flow and transport processes, since we can now explicitly calculate the dispersion coefficient even in evolving geometries. Further research may certainly address the situation of clogging by means of numerical studies. Finally, improved predictions of breakthrough curves as well as facilitated modeling of mixing and separation processes are possible.
薄带中生物膜生长的放大模型
影响因子：
5.4
作者：
van Noorden;Ebigbo;Helmig
通讯作者：
Helmig
影响因子：
2.9
作者：
X. Xuan
通讯作者：
X. Xuan