Finite-Element Method for Computing Three-Dimensional Electromagnetic Fields in Inhomogeneous Media (1993)

摘要

An efficient and accurate finite-element method is described for computing three-dimensional time-harmonic electromagnetic fields in strongly inhomogeneous, (an)isotropic media, such as are encountered in the human body, subsurface structures of the earth and in many engineering applications. For the expansion of the field in an inhomogeneous configuration, Cartesian (nodal) elements are used in its homogeneous subdomains and edge elements are used to account for the continuity relations of the field across the interfaces between those subdomains. In the domain of computation the FEMAX package in which this approach has been implemented decides locally what type of element has to be used for obtaining the user-specified accuracy of modeling the field. In this way, optimum results are obtained both in regard to computational efficiency and in regard to desired accuracy. The electromagnetic compatibility relations are used for elimination of spurious solutions. Numerical results are presented that demonstrate the package to be efficient as well as accurate.