In many different fields of engineering design like automotive industry or civil engineering, room acoustical models are used, which build up the acoustic fluid coupled with structural elements. In order to get a spatial distribution of the results containing phase-information very often methods, based on Finite Element formulations are used instead of energy methods. To obtain robust results, for example concerning small changes in geometry, especially in a higher frequency range energetically averaging processes over ensembles could be carried out in the post processing. To reduce the numerical effort for such applications a model order reduction method, based on a Component Mode Synthesis (CMS), is presented in this paper. Macrostructures are assembled out of single substructures applying global shape functions at the interfaces. These substructures, containing acoustical design elements like absorbers or resonators, are calculated separately in the frame of the CMS approach. In the substructures the acoustic fluid is modeled with the Spectral Finite Element Method for complex geometries and plate like compound absorbers, where the porous foam is specified by the Theory of Porous Media, are coupled with the air via impedances in the scope of a Ritz approach. Results are presented for the strongly coupled system.     «

In many different fields of engineering design like automotive industry or civil engineering, room acoustical models are used, which build up the acoustic fluid coupled with structural elements. In order to get a spatial distribution of the results containing phase-information very often methods, based on Finite Element formulations are used instead of energy methods. To obtain robust results, for example concerning small changes in geometry, especially in a higher frequency range energetically...     »