Please use this identifier to cite or link to this item: http://scholarbank.nus.edu.sg/handle/10635/35859
Title: Nonlinear Electrokinetic Flow near Permselective Membrane
Authors: PHAM VAN SANG
Keywords: instability, Poinsson Nernt Planck equations, sheared electroconvection, finite volume method, overlimiting current, permselective membrane
Issue Date: 8-Aug-2012
Source: PHAM VAN SANG (2012-08-08). Nonlinear Electrokinetic Flow near Permselective Membrane. ScholarBank@NUS Repository.
Abstract: We conducted numerical studies on the nonlinear electrokinetic flow developing near permselective membrane. Numerical methods were developed to solve for the Poisson-Nernst-Planck-Navier-Stokes equations. It was demonstrated that, under a significantly high electric field, an electroconvective instability occurs near the membrane surface. In quiescent electrolyte, the instability induces strong paired vortices. These vortices transport more ions to the membrane to promote an overlimiting current. Importantly, we observed hysteretic behaviors of electric current and fluid flow in the transition between the limiting and overlimiting regimes. In sheared electrolyte flow, a new kind of electroconvective instability, namely sheared electroconvective instability, was investigated. This kind of instability exhibits a unidirectional vortices flow and growing depletion zones on the membrane surface. Our findings are in agreement with experimental results. This agreement allows us to gain a fuller understanding of the mechanism for overlimiting conductance in electrodialysis cells.
URI: http://scholarbank.nus.edu.sg/handle/10635/35859
Appears in Collections:Ph.D Theses (Open)

Show full item record
Files in This Item:
File Description SizeFormatAccess SettingsVersion 
PhamVS.pdf4.71 MBAdobe PDF

OPEN

NoneView/Download

Page view(s)

209
checked on Dec 11, 2017

Download(s)

273
checked on Dec 11, 2017

Google ScholarTM

Check


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.