Assessment of the vehicle’s interior wind noise due to measurement of exterior flow quantities in early project phases

Abstract

The optimal styling of the exterior surface of a vehicle and its suspension system has a direct impact on interior wind noise. Both are determined in early project phases when typically no hardware prototype is available. Turbulent flows produce both external pressure fluctuations at the vehicle shell, known as hydrodynamic excitation, and sound waves, known as acoustic excitation. Hydrodynamic and acoustic sound sources are evaluated separately and relative to each other in the frequency domain in order to perform evaluations of different body shapes. The technical aim of the presented work is to investigate how acoustic quantities measured either directly in the exterior flow or as characteristic values of surface subsystems at the outside of a vehicle can be used to assess the influence of styling modifications to interior sound pressure level. The methodology is required to be capable of being integrated into the serial development process and therefore be quickly applicable. MAGNA STEYR Engineering has conducted extensive research to develop a method to ensure the best option is selected in early project stages.