A unified variational approach to domain-based computation of exterior problems of time-harmonic acoustics

A general framework for domain-based computation in unbounded regions, with particular reference to time-harmonic acoustics, is based on a functional for partitioned problems, weakly enforcing continuity of inner and outer fields. Two prominent features of this formulation simplify the task of discretization: the lack of integration over the unbounded domain, and accommodation of incompatible approximations. The specific formulation depends on the representation of the outer field. Examples of formulations employing DtN boundary conditions are reproduced. A novel approach to infinite element formulations is presented, leading to various approximations for two-dimensional configurations with circular interfaces. Numerical results demonstrate the good performance of these schemes.