Roman Zeyde, M.Sc. Thesis Seminar
Wednesday, 7.11.2012, 12:30
A numerical framework for the simulation of electrokinetic migration of
particles in an electrolyte solution due to the application of an external
electric field is presented.
The electrokinetic transport process is described by a system of nonlinear
partial differential equations (PDE). A thin boundary layer forms around
the particle due to strong electrostatic forces. The resulting scale disparity
of the boundary layer is used to derive nonlinear effective boundary conditions
for the numerical solver using the specific chemical properties of the particle.
The nonlinear system is discretized and an iterative Newton solver is constructed
automatically from the discrete equations and boundary conditions.
An asymptotic analytical solution is derived for the validation of the solver.
Numerical results are obtained for an ion-exchanger and for a surface charged
inert particle. The numerical results are compared to the asymptotic solutions,
and good correspondence is achieved.