Measurement of Sound Pressure Contributions in Pass-By-Noise Tests Using Particle Velocity Sensors

Abstract

In conventional pass-by-noise tests, the vehicle noise emission levelisdetermined with amicrophone at aspecifieddistance from atest track while the vehicle drivesby. Although these tests offer asimple approach to assess the overall performance, theydonot yield information about the sources of noise distributed across the vehicle. Methods to determine the influence of local excitations can be useful for manufacturs attempting to apply an effective noise reduction treatment. Acoustic beamforming methods can be applied at high frequencies for moving structures to locate noise, butthey have difficulties quantifying the impact of each source on the sound pressure next to the test track. In this paper,amethod is presented to determine the sound pressure contributions using apanel noise approach based on direct measurements of particle velocity.The sound pressure contribution for separate car positions is calculated by combining the sound radiation and the acoustic transfer path. The time-averaged result, representing the sound radiated from avehicle driving by,isultimately obtained by spatially averaging the contributions at these positions. To validate the methodology,am easurement wasp erformed with as et of loudspeakers mounted on ac ar.T he measurement method and test results are presented, and the advantages and limitations of the novelmethod are discussed.

Power-based application of frequency-averaged 𝓁1-norm regularisation technique for the synthesis of accelerating indoor tyre pass-by noise

“…However, despite their good accuracy, they are mostly suited for pass-by noise estimation on the basis of the CAD/CAE computer models, early in the design stage. In [7], tyre pass-by noise is calculated experimentally using particle velocity sensors, which can prove impractical at capturing aeroacoustic phenomena, while, in [8], a separate test-bed diagnosis is needed for tyre noise estimation.…”