On the use of a high-order finite element - wave based method for interior acoustic cavity analysis

This paper discusses the use of wave based prediction methods for the analysis of steady-state interior acoustic problems. Conventional element based prediction methods, such as the finite element method (FEM), are commonly used, but are restricted to low-frequency applications. The wave based method (WBM) is an alternative deterministic technique which is based on the indirect Trefftz approach. The WBM is computationally very efficient, allowing the analysis of problems at higher frequencies. The efficiency of the WBM is most pronounced for problems of moderate geometrical complexity. For the analysis of problems with a more complex geometry, a hybrid finite element-wave based method is developed. This hybrid approach combines the strengths of the two methods, namely, the high computational efficiency of the WBM and the ability of the FEM to model problems of arbitrary geometrical complexity. Up till now, only low-order FE models have been coupled with WB models. This paper discusses the application of more accurate high-order FE schemes in the hybrid FE-WB approach. The performance of the resulting high-order hybrid method will be illustrated by means of a numerical validation example.