TY - JOUR T1 - A Modified Helmholtz Equation with Impedance Boundary Conditions AU - Callihan , Robert S. AU - Wood , Aihua W. JO - Advances in Applied Mathematics and Mechanics VL - 6 SP - 703 EP - 718 PY - 2012 DA - 2012/12 SN - 4 DO - http://doi.org/10.4208/aamm.12-12S02 UR - https://global-sci.org/intro/article_detail/aamm/144.html KW - Helmholtz equation, impedance boundary conditions, finite element method. AB -

Here considered is the problem of transient electromagnetic scattering from overfilled cavities embedded in an impedance ground plane. An artificial boundary condition is introduced on a semicircle enclosing the cavity that couples the fields from the infinite exterior domain to those fields inside.  A Green's function solution is obtained for the exterior domain, while the interior problem is solved using finite element method. Well-posedness of the associated variational formulation is achieved and convergence and stability of the numerical scheme are confirmed. Numerical experiments show the accuracy and robustness of the method.