Ineffective magnetic core

hello guy's
I have a problem with Maxwell 2d when I as follows:

This chart will deliver me:

I need to wire up the groove lower voltage induction but in practice magnetic core are Ineffective...
why?!

The kind of magnetic problem simulated here is almost mysterious. The plots urgently need description.

thank's Let's explain some:
This is a Dentate ferromagnetic core in front of a magnet.
The flux density is different grooves and indentations.
When the core was moving horizontally perpendicular to the magnetic field
Induction voltage wires inside the groove and the tooth matched.
If necessary,send your email to my PV's that i send the project file to you.
thank's a lot