A Fluid-Structure Interaction Scheme for Prediction of Flow-Induced Low Frequency Booming Noise 2018-01-1521

The analysis of the acoustic behavior of flow fields has gained importance in recent years, especially in the automotive industry. The comfort of the driver is heavily influenced by the noise levels and characteristics, especially during long distance drives. Simulation tools can help to analyze the acoustic properties of a car at an early stage of the development process. This work focuses on the low-frequency sound effects, which can be a significant noise component under certain operating conditions. As a first step in the fluid-structure interaction workflow, the flow around a series-production vehicle is simulated, including passenger cabin and underhood flow. The complexity of this model poses extensive demands on the simulation software, concerning meshing, turbulence modeling and level of parallelism. We conducted a transient simulation of the compressible fluid flow, using a hybrid RANS/LES approach. To validate the numerical results, acoustic and surface pressure measurements were taken in an acoustic wind tunnel. We show that the simulation results are in good agreement with the experimental data. Our results demonstrate the general feasibility to simulate the flow around a complex vehicle geometry with sufficient accuracy.

In a next step, vibroacoustic methods will be applied to evaluate the influence of the excitation of the structure on the low-frequency booming phenomenon.