Prediction of Exterior Noise Generated by a Side-Mirror of an SUV

Wind-noise generated by turbulent flow-field around the car body is known to be one of the dominant noise mechanisms for the medium and high cruise speeds. One of the main sources of wind-noise for a passenger car traveling at 130 km/h for example is the noise generated by the side-mirror.Simulation methods predicting the aerodynamic and aero-acoustic performances of such car components at an early stage of their design cycle are of the high importance. This paper focuses on the validation of an acoustic simulation technique for side-mirror noise for observers located outside of the car compartment.A hybrid simulation approach is accounted, where flow and acoustic-fields are separated. The flow-field is computed a priori with an incompressible flow solver. The acoustic-field is then computed based on the information extracted from the CFD solver. A surface dipole based acoustic simulation technique is employed where the unsteady aerodynamic pressure loading on the side-mirror surface is treated as acoustic source field. The effect of the volumetric sources is then accounted in the surface source definition. The final paper will provide the acoustic simulations for different side mirrors. Results will also be compared to data obtained in wind-tunnel measurement around the SUV.