Hi,
I came to a question when applying the Neumann boundary condition in my simulation. I want to model the case of injecting fixed current into a conductor through a very thin wire. What I did is to divide the current by the cross section of the wire to get the current density (flux), which is on the order of 10^10 A/m^2. Then I solve the poisson equation with the Neumann boundary condition with a near condition to choose the contact area between the conductor and the wire. The resulting potential is very high on the order of 10^21. I wander if the surface integral in the variational problem is properly performed such that the current (flowrate) is correctly reproduced. Will the mesh size be an issue in this case? I guess I have to make sure the mesh size is much smaller than the contact area? Thanks for any ideas.