I made the following construction in COMSOL (This is a cut):
Two cylinders, the inner one in the middle is a solid cylindrical conductor. The thick outer cylindrical shell, along with the two small cylinders above and below the even smaller middle one, represent air.
I set the space charge density of the conductor (the small cylinder in the middle), I applied a tetrahedral meshing to the conductor and a swept mesh to the surroundings. After running the simulation, I was interested in the potential over the surface of the conductor, here's what it looked like:
There is clearly an inconsistency in the plot above, since the potential is constant over the surface of a conductor, the plot should be monochromatic.
Link to the relevant .mph file.
Any help would be much appreciated.