Numerical and spectral investigations of Trefftz infinite elements

The numerical and spectral performance of novel infinite elements for exter ior problems of time-harmonic acoustics are examined. The formulation is ba sed on a functional which provides a general framework for domain-based com putation of exterior problems. Two prominent features simplify the task of discretization: the infinite elements mesh the interface only and need not match the finite elements on the interface. Various infinite element approx imations for two-dimensional configurations with circular interfaces are re viewed. Numerical results demonstrate the good performance of these schemes . A simple study points to the proper interpretation of spectral results fo r the formulation. The spectral properties of these infinite elements are e xamined with a view to the representation of physics and efficient numerica l solution. Copyright (C) 1999 John Wiley & Sons, Ltd.