TEMagn1: Transient eddy currents in a semi-infinite solid

Problem Type:
A plane problem of transient magnetics.

Geometry:

The surface of semi-infinite solid plate is suddenly subjected to a constant magnetic potential A0.

Given:
Magnetic permeability of material μ = 1;
Conductivity of material g = 2,500,000 S/m;
Loading A0 = 2 Wb/m.

Problem:
Determine current distribution within the conductor.

Solution:
The model length 20 m is arbitrarily selected such that no significant potential change occurs at the end points for the time period of interest. The final time of 0.25 s is sufficient for the theoretical response comparison. A time step of 0.005 s is used.

Comparison of Results:
 

Time t = 0.15 s

Coordinate x,m

QuickField

ANSYS

Theory

Vector Potential A, Wb/m

0.2517

0.822

0.831

0.831

0.4547

0.280

0.278

0.282

0.6914

0.053

0.044

0.05

Flux Density B, T

0.2517

3.692

3.687

3.707

0.4547

1.716

1.794

1.749

0.6914

0.418

0.454

0.422

Eddy Current Density j, A/mm2

0.2517

-8.06

-7.80

-7.77

0.4547

-6.56

-6.77

-6.63

0.6914

-2.34

-2.45

-2.43

See the TEMagn1.pbm problem in the Examples folder.