Stacked magnets with air gaps and the effect on magnetic flux

[bobsback99]

I wasn't sure where to put this so mods feel free to move,
So this is a problem I'm trying to solve for a masters project and simplified it is this;

I essentially have a stack of magnets all separated by 4mm each magnet is identical and produces a magnetic flux of 17.5 gauss at its centre (all there fields are facing the same direction), in this state what will the total flux be at one of the ends or at any axial z distance?

You can treat the magnets as height 0 because in real life they are a series of planar coil electromagnets, and for the sake of simplicity we will say each has its own core but in fact there is 1 mild steel core of relative permeability K = 130.

If anyone knows how to solve this or can give me pointer where to look i would be v grateful.

 

[BiGyElLoWhAt]

Is there a reason why the Biot-Savart law plus superposition won't give you the desired result?
http://en.wikipedia.org/wiki/Biot–Savart_law#Equation