Solving acoustics problems using the boundary element method (BEM) can be very advantageous compared to the finite element method (FEM) for some types of problems. For others problems, FEM has its advantages. The recommended approach is to use the BEM and FEM methods where they apply best and also to combine them. Since the BEM interface is fully enabled with multiphysics capabilities, it can be coupled seamlessly with the physics interfaces that are based on FEM. This functionality includes coupling to vibrating structures with the Acoustic-Structure Boundary multiphysics coupling and to other acoustic domains with the Acoustic FEM-BEM Boundary multiphysics coupling. This approach enables modeling in a FEM-BEM framework, using the strength of each formulation adequately. The BEM-based interface is especially well suited for radiation and scattering problems.

The advantage of the boundary element method is that only boundaries need to be meshed and the DOFs solved for are restricted to the boundaries. This introduces some clear ease-of-use for handling complex geometries. However, the BEM technique results in fully populated or dense matrices that need dedicated numerical methods. Assembling and solving these matrices can be very demanding. This means that when solving acoustic models of small and medium size, The Pressure Acoustics, Frequency Domain Interface will often be faster than solving the same problem with the BEM interface.

Note also that at very low frequencies, the BEM method may “break down” for interior problems and give inaccurate results. This is in practice not an issue, as this kind of problem should be solved with The Pressure Acoustics, Frequency Domain Interface.