Sb. Railkar et al., DEVELOPMENT OF MATHEMATICAL TOOLS TO DETERMINE OPTIMUM ENCLOSURE DESIGNS FOR CONTROLLING ELECTROMAGNETIC-FIELDS, Journal of reinforced plastics and composites, 12(11), 1993, pp. 1212-1220
Electromagnetic fields are present wherever sources of currents are fo
und. Conventional shielding against these electromagnetic fields is ac
complished by using complete ferromagnetic enclosures. Maxwell's equat
ions govern the phenomenon of electromagnetic fields in discontinuous
media, and analytical solutions in the presence of enclosures of arbit
rary shapes are not available. Hence, Maxwell's equations are solved n
umerically using the finite element method in conjunction with the mag
netic scalar potential approach. The test case for the verification of
the numerical code is a long cylindrical ferromagnetic shell placed i
n a transverse uniform magnetic field for which an analytical solution
is derived here. The comparison of analytical and numerical solutions
validates the accuracy of the numerical code. As expected the magneti
c field inside the complete enclosure varies inversely to the relative
permeability of the enclosure. Using this approach, enclosures of dif
ferent shapes can be designed.