Scaling of the simulated pass-by measurement based on the vehicle's acoustic centre

Abstract

Preliminary work by the IPEK - Institute of Product Engineering at KIT has shown that the simulated pass-by measurement for exterior noise homologation of vehicles has relevant optimization potential: the measurement can be carried out in smaller halls and with a smaller measurement setup than required by the standard and thus with less building construction cost and measurement effort. A prerequisite for this, however, is the scaling of the entire setup. For the scaling to work correctly, the sound sources of the vehicle must be combined to a single point sound source - the acoustic centre. Therefore, in a preliminary work, the IPEK developed a method, with the help of which the dominant sound sources of a vehicle can be localized and combined to an acoustic centre. In this work, the method is applied exemplarily on two test vehicles and their acoustic centres are determined. Afterwards, the measurement setups for both vehicles are scaled based on the acoustic centres, Finally, the simulated pass-by measurement with the scaled measurement setup is performed on an acoustic roller test bench and the scaled sound pressure levels are determined. To verify the overall method, the results of the scaled pass-by measurements are compared with the unscaled one and with measurements on the test track.