Finite Elements for the Computation of Three-Dimensional Electromagnetic Fields in Inhomogeneous Media (Revised)

摘要

A new type of vectorial expansion functions for the finite-element modeling of three-dimensional propagation- and induction-type electromagnetic fields is capable of handling the field near interfaces of discontinuity in the electromagnetic properties of the media more accurately than previous known ones, and is therefore to be preferred when computing electromagnetic fields in, for example, borehole configurations. To test their efficiency as compared with conventional elements, the field in a mathematical model configuration is analyzed. A performance coefficient expresses the relative effiencies of different types of elements. For the test problem, the elements prove to be superior, especially when the media are strongly inhomogeneous. For weakly inhomogeneous media, the conventional elements are more efficient.