Fringing flux can have high magnitude around the air gap in a gapped core. With a normally laminated core two sides expose large surface area of the laminations and the fringing flux leaves and enters the core at large angle producing significant planar eddy currents and significant power loss. In high-power applications such loss can be so significant that radially laminated core must be used.
The drawing was based on:
eddy_currents_with_fringing_flux_-_magnetica.png
You are permitted and indeed encouraged to use this image freely, for any legal purpose including commercial, and with any modifications (the permission is hereby given, so there is no need to ask for it explicitly again), but you MUST always give the following credits:
S. Zurek, Encyclopedia Magnetica, CC-BY-4.0
We would appreciate if you let us know of any use: info@e-magnetica.pl