To find leakage inductance of a toroidal transformer

Hello,

I am trying to find the leakage inductance of toroidal transformer using a 3D model. I made a 3D model using the equivalent Copper conductors as a single winding (not each windings separately).Then applied external current density to them. Then I found the leakage inductance from the magnetic energy density. This value is almost good when I compared with the axial symmetric model. But then I included the sector winding (or some portion of winding is kept as air), so in reality the magnetic energy density and leakage inductance should increase a lot. But I am not getting that increase in the magnetic energy density. But when I did the same using 2D top view of toroidal transformer, I am noticing this increase. Could you please help me out in this.

Thanks a lot.

Regards
Noel