Energy FEM and BEM for High Frequency Acoustics
* Presenting author
Energy based methods are an efficient way to simulate acoustics in the high frequency regime. The conventional methods, as the FEM or the BEM, require a high number of elements due to the very short wavelength. Even the high performance computing is not able to achieve results in a reasonable time for these problem, but the high frequency regime allows some assumptions that lead to possible reductions in the computational effort. The acoustical pressure and velocity are condensed to the energy density. This assumption allows for an almost frequency independent discretization of the domain. The underlying approximations enable new fields that were previously not computable. For instance, the investigation of a car interior or even a whole ship in the complete acoustical frequency range up to 20 kHz.Numerical methods that allow for these applications are the energy based counterparts EFEM and EBEM. These two methods are an alternative for the established Statistical Energy Analysis (SEA) or the Ray Tracing. The governing relations for an energy based formulation as well as the derivation of the EFEM and EBEM are presented. Especially, the differences and the range of validity are discussed, while representative examples show the efficiency of the methods.