Ye Chunzhen, Li Dongqing
Department of Mechanical and Industrial Engineering, University of Toronto, 5 King's College Road, Toronto, ON M5S 3G8, Canada.
J Colloid Interface Sci. 2004 Apr 15;272(2):480-8. doi: 10.1016/j.jcis.2003.11.014.
This paper considers the electrophoretic motion of a spherical particle in an aqueous electrolyte solution in a T-shaped rectangular microchannel, where the size of the channel is close to that of the particle. This is a complicated transient process where the electric field, the flow field, and the particle motion are coupled together. A theoretical model was developed to investigate the influences of the applied electric potentials, the zeta potentials of the channel and the particle, and the size of the particle on the particle motion. A direct numerical simulation method using the finite element method is employed. This method employs a generalized Galerkin finite element formulation that incorporates both equations of the fluid flow and equations of the particle motion into a single variational equation where the hydrodynamic interactions are eliminated. The ALE method is used to track the surface of the particle at each time step. The numerical results show that the electric field in the T-shaped microchannel is influenced by the presence of the particle, and that the particle motion is influenced by the applied electric potentials and the zeta potentials of the channel and the particle. The path of the particle motion is dominated by the local electric field and the ratio of the zeta potential of the channel to that of the particle. The particle's velocity is also dependent on its size in a small channel.
本文研究了球形颗粒在T形矩形微通道内的水性电解质溶液中的电泳运动，该微通道尺寸与颗粒尺寸相近。这是一个复杂的瞬态过程，电场、流场和颗粒运动相互耦合。建立了一个理论模型，以研究外加电势、通道和颗粒的zeta电势以及颗粒尺寸对颗粒运动的影响。采用了一种基于有限元法的直接数值模拟方法。该方法采用广义伽辽金有限元公式，将流体流动方程和颗粒运动方程合并为一个单一的变分方程，从而消除了流体动力学相互作用。ALE方法用于在每个时间步跟踪颗粒表面。数值结果表明，T形微通道中的电场受颗粒存在的影响，颗粒运动受外加电势以及通道和颗粒的zeta电势的影响。颗粒运动路径由局部电场以及通道zeta电势与颗粒zeta电势的比值主导。在小通道中，颗粒的速度也取决于其尺寸。
