Geometrical symmetry often occurs in computational electromagnetics. However, it is generally not taken into account when the excitations do not share this symmetry. A rationale is required, and group theory gives the only valuable tool for this purpose. It provides a symmetric decomposition of any problem that allows its study on a reduced part of the initial geometry. This way of treating field problems generally leads to substantial computational savings. The symmetry concept is applied in the paper to 3D linear eddycurrent analysis, where the numerical scheme used is a mixed FEM–BEM method. Detailed examples are presented to demonstrate the efficiency of the use of symmetry.
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