Core reluctance

QuickField simulation example

This is a QuickField simulation of the example #1-1 from the book Electric Machinery Fundamentals by Stephen J. Chapman.

Problem Type
Plane-parallel problem of DC magnetics.

Geometry
Core depth is 10 cm.

Given
Relative permeability of the core is 2500;
Coil number of turns is 200, current I is 1 A.

Task
Calculate the total reluctance of the flux path and compare it with the analytical solution.

Solution
We do not draw each individual turn. The coil is modelled as a block with the total ampere-turns specified.
Due to the crowding effect the actual magnetic flux path is shorter than the middle-line path used in the analytical calculations. So me may expect to get a higher flux value. Analytical solution* gives the flux value of 4.8 mWb

Results
Magnetic flux value is 5.5 mWb, core reluctance is 200/0.0055 = 36.4 kA·turns/Wb.

*Reference
Chapman, Stephen J. (2011). Electric Machinery Fundamentals (5th ed.). McGraw-Hill (p.14)

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