Iron sphere AC magnetic field shielding

QuickField simulation example

This is an example of the iron sphere shielding simulation performed with the QuickField software. Example is prepared by Professor James R. Claycomb as a part of the webinar QuickField for Electromagnetic Shielding Applications.

Engineering question
How to find frequency-dependent magnetic shielding by iron spheres?

Engineering answer
Set up an axisymmetric QuickField AC Magnetics problem for an iron sphere and evaluate frequency-dependent magnetic shielding from computed field results.

Typical applications
ferromagnetic spherical shields, magnetic shielding spheres, spherical shielding enclosures

• Download simulation files (files may be viewed using any QuickField Edition).

Problem Type
Axisymmetric problem of AC magnetics.

Geometry

Given
Relative magnetic permeability of steel μ = 100,
Conductivity of steel σ = 1 MS/m,
External field B = 2.0 T, frequency f = 50 Hz... 100 kHz.

Problem:
Determine the shielding factor at different frequencies.

Solution
LabelMover parametric tool is used to automate frequency sweep. LabelMover generates a set of QuickField problems (multiplying frequency by 2 at each step), simulates problems, calculates the magnetic flux density in the point of interest and place the results in the table.

Results
Magnetic field strength distribution at 50 Hz.

• Video: Iron sphere AC magnetic field shielding
  
  See more in QuickField for Electromagnetic Shielding Applications webinar.
• View simulation report in PDF