Engineering Analysis with Boundary Elements vol:55 pages:58-66
When using a domain-based method for solving problems in unbounded domains,
the computational domain has to be truncated to a bounded region.
On the truncation, suitable conditions must be imposed to ensure the solution
of the truncated problem is equivalent to the solution of the unbounded
problem. This paper proposes to derive these conditions based on an explicit
model of the unbounded domain exterior to the truncation. The Wave Based
Method (WBM), a Trefftz-based prediction technique for solving Helmholtz
problems, is used to construct this unbounded model. The WBM has proven
to be an efficient alternative for element based techniques and therefore can
be applied towards mid-frequency problems. The obtained method is compared
to the DtN FE method, where it is shown that the obtained accuracy
is equivalent, but the proposed hybrid FE-WB framework allows for a more
efficient construction and solution of the model.