Coupling Stationary fluid flow and transient solute transport to AC/DC module

Hello,

I'm not the most proficient COMSOL user yet, and I have a 2D problem in v3.5a that would seem to be rather simple but has proven difficult to me thus far. My problem is as follows:

I want to analyze the behavior of the electric field due to transient NaCl transport through a steady-state flow field inside of a 2D cross-section of a dam, given a slug injection of NaCl. The electric field is a function of the steady-state velocity field as well as the time-dependent concentration gradient of NaCl, via the external current density term, Je, in the AC/DC module.

This is the main issue for me - the electric field is coupled to both the steady-state velocity field as well as the the concentration gradient of the solute in the flow field that is changing in time, and I'm unsure of the solver sequence that is necessary to achieve the solution to evaluate the electric field through time.

Any help would be greatly appreciated.

Also, I intend to extend my 2D model to a 3D simulation. Is there a simple, straightforward way to convert my 2D geometry to a 3D geometry?

Thanks in advance,

Scott