Direct noise computation of a generic vehicle model using a finite volume method

•Acoustic damping model and grid stretching reduce spurious noise.•A-pillar is the major noise source in the absence of side mirror.•In the presence of a side mirror, the mirror is the major noise source.•Turbulent pressure fluctuations excite the window mainly below 800 Hz.•Acoustic pressure fluctuations excite the window mainly above 800 Hz. This paper demonstrates the applicability of a finite volume method for the direct noise computation of road vehicles. For this purpose, a generic vehicle model consisting of major aeroacoustic components of a production car is considered. Such components are the A-pillar and the side mirror. The flow past the vehicle model is calculated using a compressible flow solver for low Mach number flows, accompanied with an approach based on detached eddy simulation for turbulence modelling. Two variants of the vehicle model are calculated, namely with and without side mirror. Validation of aerodynamic results is performed by comparing simulated surface pressure spectra on the side window to wind tunnel measurements. Thereafter, acoustic waves generation and propagation are examined. The propagation of acoustic waves from the sources to the windows surface is calculated directly using the compressible solver, as well as indirectly using a surface integral method. The results of both methods are then used as an input for a vibroacoustic model and surface acceleration spectra are compared between both approaches and wind tunnel measurements. A general assessment of both numerical approaches is given and the aeroacoustic impact of the A-pillar as well as the side mirror regarding their contribution to the overall acoustic level is presented.