A coupled BEM and energy flow method for mid-high frequency internal acoustic

This paper deals with the behaviour of acoustic cavities in the mid-high frequency range. The method proposed here is based on an energy flow method named Simplified Energy Method (MES). MES method is quite efficient in the mid-high frequency range but the directivity of the boundary sources is not well estimated. We propose a hybrid method which couples MES and the Boundary Element Method (BEM). Thus, the BEM method is used to estimate the direct field, considering a “correct” directivity. As a complete calculation is not adapted to BEM in mid-high frequency range because of the calculation costs, we only apply BEM on the domains including boundary sources. Other parts of the system and the reverberated field are estimated by the mean of MES method. This hybrid method leads to a consistent prediction of injected power densities. Numerical comparisons prove the efficiency of the proposed reformulation. keywords: Energy flow; BEM; Energy method; Injected power density; Energy density; Intensity.