Numerical methods based on a shooting technique are employed to determine the electric potential and fluid velocity in a tube and channel when the zeta poten- tial is not small. In addition, new analytical solutions are presented for the fluid velocity in the extreme of a small Debye layer thickness. Asymptotic expressions for these results are provided for the limits of small and large zeta potentials. We find that increasing values of the wall potential always increase the mean fluid speed and yield a velocity profile having a more uniform speed near the center of the tube or channel.
Journal: TechConnect Briefs
Volume: Technical Proceedings of the 2000 International Conference on Modeling and Simulation of Microsystems
Published: March 27, 2000
Pages: 532 - 535
Industry sector: Sensors, MEMS, Electronics
Topicss: Informatics, Modeling & Simulation, Micro & Bio Fluidics, Lab-on-Chip