An Efficient Hybrid Computational Process for Interior Noise Prediction in Aeroacoustic Vehicle Development 2023-01-1120

The implementation and application of numerical methodologies for aeroacoustic analysis becomes more and more essential for car manufacturers in order to optimize the effectiveness of vehicle development. In the present work, a hybrid numerical tool based on the combination of a delayed detached eddy simulation and a finite element model based on the Lighthill’s acoustic analogy and the acoustic perturbation equations is presented. The computational aeroacoustics is performed by the software OpenFOAM and Actran with respect to the CFD and the FEM respectively. The aeroacoustic behavior of the SUV Lamborghini Urus at a cruising speed of 140 km/h has been investigated. The main aerodynamic noise phenomena in the side mirror region are discussed in a frequency range up to 5 kHz. The numerical simulations have been verified against the measurements performed in the aeroacoustic wind tunnel of the University of Stuttgart, operated by FKFS. The predicted exterior noise propagation into the far field has been validated by comparing the sound pressure level, defined as the acoustic contribution to the total pressure fluctuation, with the experimental data measured by exterior microphones located outside the turbulent region right beside the wake of the side mirror. Furthermore, the location of the most critical aeroacoustic sources has been validated by means of beamforming measurements in the wind tunnel. Lastly, the noise transmission into the cabin through the side window has been modelled. Simulation results have been validated by the analysis of the sound pressure level measured by interior microphones installed on the driver seat. Both the exterior and the interior noise predictions have shown very good correlations with experiments. Therefore, the CAA process has been proven to be suitable for combined analysis between the generation mechanisms of wind noise and the resulting transfer into the interior cabin to the driver’s ear.