Acoustic simulation in HPC and cloud environment

Acoustic simulation test case was performed with Kuava Oy's software application Waveller Cloud. It uses CompA algorithm which is based on the boundary element method (BEM) for solving the acoustic wave equation in frequency domain. BEM is mostly used and best applicable to exterior problems and in this context it was used to interior problems where it is not as efficient as the finite element method (FEM). Furthermore, a true fluid-structure interaction and propagating waves in structures cannot be modelled only using BEM as they can with coupled vibro-acoustic FEM, only locally reacting boundary conditions (impedance) for acoustic fields can be associated to the boundary structures. This may cause errors with individual strongly coupled near-by surface parts especially if the individual surface properties deviate much from each other. The case study, Valtra cabin T888M, was concentrated on the sound field distributions produced by an acoustic point source into the interior of a tractor cabin, and simulation of material utilization in three inner roof elements for which calculated results exist based on FEM simulations in NOVI project. Probably the main reason for the largely different results of the sound pressure level distributions in the cabin at 100 Hz of Waveller Cloud calculations, compared to those of Actran, for the inner roof case 1 is treating separately and as locally reacting the centre and outer parts of the inner roof. Also the small deviations in the sound field distributions for the inner roof cases 2 and 3 are probably due to the handling of some affecting things in a different manner in FEM and BEM models. Otherwise, these computed results are tolerably in agreement. Using BEM in interior problems is very sensitive to proper impedance definitions of the boundaries.