Efficient treatment of singularities in wave based models for 2D acoustic scattering problems

The Wave Based Method is an efficient prediction technique based on a Trefftz approach which can be applied in a wide frequency range. This paper discusses the particular case of 2D unbounded acoustic problems where singularities are present in the corners of the calculation domain. As it has been shown for structural and poro-elastic applications, the Wave Based accuracy deteriorates when stress singularities are present in the calculation domain. By adding special purpose functions which exactly incorporate the singular behaviour, a better accuracy and convergence characteristics were gained. This paper investigates when singularities are present in corners of 2D acoustic problem domains and how they can be tackled efficiently. The conventional set of expansion functions used to approximate the dynamic pressure field is extended with special purpose enrichment functions which incorporate the singular behaviour in the vicinity of the singular corners. This enrichment comes with a beneficial convergence rate while only a small increase of computational effort is incurred as shown by a numerical validation example.status: publishe