Sound energy-based surface contribution analysis for the vehicle interior noise problem

Abstract

Booming noise is a major comfort problem in vehicle cabins occurring in lower frequencies. The method of panel or surface analysis serves as a viable tool to trace the sound emitting components on the enveloping chassis. Traditional techniques evaluate the surface contributions with respect to the sound pressure level at the driver’s position. However, using the sound pressure level as the control objective implies two major drawbacks: Firstly, the local sound pressure is highly sensitive to the position of the evaluation point. As a consequence, the predictions of the surface contributions become unreliable at frequencies or areas with low sound pressure levels. Secondly, surface contributions in existing techniques can be positive or negative, which facilitates the event of acoustic shortcircuits. This talk presents an accurate and robust contribution analysis method for the vehicle interior noise problem. For this purpose, the sound energy density is used as the control objective. A quadratic form yields energy-based contributions, which are always non-negative and thus avoiding acoustic shortcircuits. These findings demonstrate that contributing surface are effectively identified even in regions with sound pressure levels. As such, the evidence from this study suggests that the sound energy density provides an accurate and robust control objective.