Vibro-Acoustic Simulation of Intake Air Filter Using a Hybrid Modal Physical Coupling 2012-01-1549
To assess the acoustic performance of modern automotive air filters, both the air-borne engine noise propagating through the interior air of the system (known as “pipe noise”) and the structure-borne noise radiated by the shell (“shell noise”) should be evaluated. In this paper, these different propagation paths are modeled using the finite element solver Actran on industrial test cases set-up by SOGEFI Air and Cooling Systems.
The test-case is designed in such a way that the different propagation paths are assessed separately. First the engine acoustic pulsation that is transmitted through the filter's structure is considered. Second, the noise radiated by the shell excited by mechanical forces at the support location of the filter is evaluated. Finally, the acoustic transmission loss of the filter is predicted.
The ingredients of the finite/infinite element models are reviewed in details in the paper. In particular, the recently implemented modal/physical coupling is successfully applied to benefit from an existing modal representation of the structure of the filter. Using this approach, the acoustic CAE engineer does not need to create a new mesh for the structure of the filter and can thus focus on the modeling of the acoustics. The results of the simulation are compared with measurements data.