Direct numerical simulation of electroconvective instability and hysteretic current-voltage response of a permselective membrane
Direct numerical simulation of electroconvective instability and hysteretic current-voltage response of a permselective membrane
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DOI：
10.1103/physreve.86.046310
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发表时间：
2012-10-11
影响因子：
2.4
通讯作者：
Han, Jongyoon
中科院分区：
文献类型：
--
作者：
Pham, Van Sang;Li, Zirui;Han, Jongyoon
我们提出了一个系统的，多尺度的，充分详细的数值模拟的流体流动和离子传输的动态覆盖欧姆，限制，并在离子选择性膜的电导过限电流制度。通过数值求解Poisson-Nernst-Planck-Navier-Stokes方程，证明了电场作用于扩展的空间电荷层所引起的电对流不稳定性和诱导的强涡旋流体流动是导致平板膜系统过限电流的主要因素.更重要的是，在限制和过限制电流制度之间的过渡，电流的滞后被识别。电滞现象说明了电对流在离子选择性膜电解质体系中对电流增强的重要作用。
We present a systematic, multiscale, fully detailed numerical modeling for dynamics of fluid flow and ion transport covering Ohmic, limiting, and overlimiting current regimes in conductance of ion-selective membrane. By numerically solving the Poisson-Nernst-Planck-Navier-Stokes equations, it is demonstrated that the electroconvective instability, arising from the electric field acting upon the extended space charge layer, and the induced strong vortical fluid flow are the dominant factors of the overlimiting current in the planar membrane system. More importantly, at the transition between the limiting and the overlimiting current regimes, hysteresis of electric current is identified. The hysteresis demonstrates the important role of the electroconvective flow in enhancing of current in electrolyte systems with ion-selective membrane.