Development and validation of a computational methodology for the calculation of fluid-structure-acoustic interactions on a simplified car model

In the sound spectrum of passenger cars, the turbulence development behind the side mirror is a highly significant process, as the interactions of the turbulent structures with the side window lead to vibration and thus to sound radiation into the vehicle interior. Therefore, the understanding of the coupling of exterior flow, structural vibration and sound propagation is crucial for a simulative reproduction and the realistic prediction of the perceptible sound spectrum inside the vehicle. While previous investigations focused mainly on isolated aspects of the described test case, this study aims at the introduction of a complete simulative methodology, which also includes the window clamping elasticity and the acoustic properties of the vehicle interior. The main challenge lies in the implementation of the coupling strategy, as the accuracy of the fluid-structure-acoustic interaction at the side window is essential for the result quality. Considering different coupling approaches a one-way data transfer between flow and structure is chosen, while the acoustic propagation is fully coupled to the window vibration through a calculation in the frequency domain. The simulation results are in good accordance with wind tunnel measurements, but also show local deviations, which are subject to a final discussion.