Numerical solutions of low-frequency scattering problems

Low-frequency scattering problems are analyzed through the solution of partial differential equations, imposing appropriate open boundary conditions. A 2-D FEM (finite element method) procedure is developed to solve Helmholtz's equation in terms of the scattered electric or magnetic fields, where the forcing terms are functions of the incident fields. In the low-frequency range, the scattering is assumed to be isotropic, and the expressions of the open boundary formulations are simplified. Wave impedance boundary conditions for the scattered fields are introduced. The results obtained by utilizing different open boundary conditions in a test configuration are compared.<>