Im Do Jin, Kang In Seok
Department of Chemical Engineering, Pohang University of Science and Technology, San 31, Hyoja-dong, Pohang 790-784, South Korea.
J Colloid Interface Sci. 2003 Oct 1;266(1):127-40. doi: 10.1016/s0021-9797(03)00546-0.
We consider the electrohydrodynamics of a spherical drop in a nonaxisymmetric electric field, which can be approximated by the sum of a uniform field and a linear straining field. We obtain the analytic solution of the three-dimensional flow fields inside and outside a drop for the Stokes flow regime by using Lamb's general solution and the leaky dielectric model. With the analytic solution, the dielectrophoretic migration velocity of a drop is obtained as a function of the type and the frequency of the imposed electric field. The direction of drop motion is found to be parallel to the dielectrophoretic force. The analytic solution is also used to investigate the characteristics of the interfacial flow under various nonaxisymmetric electric fields. While investigating the interfacial flow, we find a surface vortex structure under certain nonaxisymmetric electric fields, which is found to be related to the chaotic mixing inside the drop. Finally, we consider the chaotic features of three-dimensional flows inside the drop under static nonaxisymmetric electric fields.
我们考虑在非轴对称电场中球形液滴的电流体动力学，该电场可近似为均匀场和线性应变场之和。通过使用兰姆通解和漏电介质模型，我们得到了斯托克斯流态下液滴内外三维流场的解析解。利用该解析解，得到了液滴的介电泳迁移速度与外加电场类型和频率的函数关系。发现液滴运动方向与介电泳力平行。该解析解还用于研究各种非轴对称电场下的界面流特性。在研究界面流时，我们发现在某些非轴对称电场下存在表面涡旋结构，该结构与液滴内部的混沌混合有关。最后，我们考虑静态非轴对称电场下液滴内部三维流的混沌特性。
