Electrochemistry

Hello,
I am new in Comsol. I want to model a channel flow cell with hydrodynamic condition that I am using in cyclic voltammetry . And flow rate assumed to be variable here. I wanted to know if anyone had any suggestions on how to get start doing this using COMSOL as I am new. How to model elctrode and also channel in my simulation. I would like to be able to plot current vs potential at different flow rates.
Thanks