Electrophoresis of a Cylinder in a Cylindrical Tube. (28th July 2017)

• Record Type: Journal Article
• Authors: Feng, Huicheng; Wong, Teck Neng
• Is Part Of: Communications in computational physics. Volume 22:Number 4(2017:Oct.)
• Page Start: 1101
• Page End: 1122
• Publication Date: 2017-07-28
• Subjects: 76W05; Electrophoresis, -- cylindrical tube, -- vortex generation, -- cylinder rotation; Mathematical physics -- Data processing -- Periodicals; Physics -- Data processing -- Periodicals; 530.150285
• DOI: 10.4208/cicp.OA-2017-0011
• Languages: English
• ISSNs: 1815-2406

Abstract

Abstract: Electrophoresis of a cylinder suspended in a cylindrical tube is analytically studied in the limit of thin electric double layer approximation. The electric and fluid flow fields within the annulus, and the cylinder velocities are analytically obtained in bipolar coordinates. The results are analyzed with various values of dimensionless parameters: eccentricity, cylinder-to-tube radius ratio and tube-to-cylinder zeta potential ratio (i.e., tube-to-cylinder velocity scale ratio). The analysis shows that microvortices are generated within the annulus. By changing the parameters, different flow patterns can be created, which shows potential for mixing enhancement in micro/nanofluidics. Moreover, the cylinder not only translates but also rotates when the cylinder and tube are eccentric. The cylinder rotation might be utilized as a micromotor or an electric field detector. The cylinder trajectories show that the cylinder may approach the tube wall or rest within the tube depending on the zeta potential ratio.