Van der Auweraer, H., Bianciardi, F., Van de Ponseele, P., and Janssens, K., "Transfer Path Analysis Innovations for Airborne Noise Problems with Focus on Pass-By-Noise," SAE Technical Paper 2014-36-0801, 2014, doi:10.4271/2014-36-0801.
The Transfer Path Analysis method is at the core of the Source-Transfer-Receiver approach to address noise and vibration problems. While originally developed for analyzing structure-borne noise transmission, its application range has been extended to airborne noise. Various frequency and time domain approaches have been developed with a focus of supporting specific design engineering problems.One such application is the source contribution analysis in the context of vehicle pass-by-noise. The upcoming changes in the pass-by noise regulation will not only require more complex tests in different conditions but most importantly, the new directive will force car manufacturers to further reduce the emitted noise levels of their vehicles. Enhanced engineering techniques that allow quantifying noise contributions of vehicle subsystem components (engine, intake, gearbox, tire, exhaust, etc.) are essential to enable the OEM to validate and improve designs for pass-by noise targets, early in the design process.An overview of different source contribution analysis methods applicable for pass-by noise is presented. Three techniques are compared in more detail: a traditional pressure inversion method, a power-based approach, and a signal processing technique using a transmissibility approach. The paper reviews the main principles of the techniques, their advantages and disadvantages, and the major selection criteria. Various application examples are presented, including a passenger car with internal combustion engine, a motorbike, and an electric vehicle. It is also demonstrated how this airborne TPA approach can be included in a sound synthesis framework, extending it to sound quality engineering solution.