Efficient Integrated Vibro-Acoustic Simulation Methods

The new trends in industry with for instance the electrification of systems leads to new challenges in the domains of acoustics and vibrations. The tonal noise of electric machines and their gearboxes, masked by the internal combustion engine in traditional vehicles, can now be significantly perceived by passengers, resulting in acoustic discomfort. Industry engineers now need to spend substantial effort in understanding the noise and vibration behavior of such components, with the main objectives of decreasing the weight for functional performance and reducing unpleasant sounds. Efficient vibro-acoustic simulation methods are then necessary to achieve these goals, starting from the modelling techniques up to the actual computation and solution post-processing. A complete workflow fully integrated within a single software platform is shown in this paper to achieve the simulation of a gearbox housing exterior radiation. Multiple physical aspects are included in this numerical solution through the multi-body simulation of the transmission system, and the exterior noise radiation of the gearbox housing. Vibro-acoustic solutions are described in this paper, involving the MATV (Modal Acoustic Transfer Vector) response, which makes use of the MPFs (Modal Participation Factors) obtained with the multi-body simulation in frequency domain. These MPFs are combined with the modal representation of the gearbox housing and the transfer function representation of the fluid to obtain the vibro-acoustic response. A comparison with a Time-Domain BEM (Boundary Element Method) solution is also provided, where the transient forces from the multi-body simulation are applied onto the modal representation of the gearbox housing coupled with the fluid. A good match of the solutions is shown.