An improved nodal FEM for low-frequency time-harmonic electromagnetic modeling

Abstract

Numerical modeling of geophysical electromagnetic induction problem requires solving low-frequency time-harmonic Maxwell’s equations. Conventional nodal base finite element method is not suitable for computing electromagnetic field in inhomogeneous conductivity structure. An improved nodal finite element method is proposed. In this scheme, the divergence equation of Gauss’s law is containing in the governing equations, electrical fields are decomposed into two parts of divergence-free and curl free, and a stabilizing term is introduced into the double-curl equation. The method is shown to be accurate and stable for the quasi-static electromagnetic modeling of highly discontinuous conductivity structure.