Application of a hybrid finite element-Trefftz approach for acoustic analysis

Abstract

This paper reviews a wave based prediction technique for steady-state acoustic analysis, which is being developed at the K.U. Leuven Noise and Vibration Research group. The method is a deterministic technique based on an indirect Trefftz approach. Due to its enhanced convergence rate and computational efficiency as compared to conventional element based methods, the practical frequency limitation of the technique can be shifted towards the mid-frequency range. For systems of high geometrical complexity, a hybrid coupling between wave based models and conventional finite element (FE) models is proposed in order to combine the computational efficiency of the wave based method with the high flexibility of FE with respect to geometrical complexity of the considered problem domain. The potential to comply with the mid-frequency modelling challenge through the use of the wave based technique or its hybrid variant, is illustrated for some three-dimensional acoustic validation cases.