Comparison of hydrodynamic and acoustic pressure on automotive front side window

Abstract

The unsteady flow in the front side window region of the vehicle can generate hydrodynamic and acoustic pressure on the front side window, which can influence the interior sound field. The hydrodynamic pressure on the front side window was achieved by the incompressible wall-modeled large-scale eddy simulation (WMLES) or improved delayed detached eddy simulation (IDDES), and the hybrid computational aeroacoustics (CAA) method based on acoustic perturbation equations (APE) was employed to achieve the acoustic pressure on the front side window. The numerical results of both hydrodynamic and acoustic pressure ware validated by the wind tunnel experiment, especially the corrected force analysis technique (CFAT) is employed to validate the acoustic pressure. The comparison of hydrodynamic and acoustic pressure on the front side window was performed by the Dynamic Mode Decomposition (DMD). Results show that the hydrodynamic pressure regionally distributes on the front side window and most energy concentrates on area interacted with the side mirror wake, while the acoustic pressure distributes uniformly on the front side window acting as a diffusion field and the energy disperses in frequency region.