标题：Closed-form solutions of transient electro-osmotic flow driven by AC electric field in a microannulus
作者：Wang, Shaowei; Zhao, Moli
作者机构：[Wang, Shaowei; Zhao, Moli] Shandong Univ, Sch Civil Engn, Dept Engn Mech, Jinan 250061, Peoples R China.; [Wang, Shaowei; Zhao, Moli] Shandong Univ 更多
通讯作者地址：[Wang, SW]Shandong Univ, Sch Civil Engn, Dept Engn Mech, Jinan 250061, Peoples R China.
来源：BOUNDARY VALUE PROBLEMS
关键词：transient flow; electro-osmosis flow; integral transform; velocity; distribution
摘要：The time-periodic electro-osmotic flow of Newtonian fluids through a microannulus is studied in the Debye-Huckel approximation. Analytical series solutions for velocity and flow rate are presented with the help of an integral transform. The expression for the distribution of the velocity profile consists of a time-dependent oscillating part and a time-dependent generating or transient one, and the normalized velocity function is independent of the Reynolds number, which is very different from previous results. Then the effects of the electrokinetic width K, the wall zeta potential ratio beta, and the frequency of applied external electric field omega on the distribution of the velocity profiles and flow rates are discussed numerically and theoretically. Some new physical and chemical phenomena are found theoretically. We point out that the electro-osmotic flow driven by an alternating electric field is not periodic in time, but quasi-periodic. There is a phase shift between voltage and flow, which is only dependent on the frequency of the external electric field.