Operational transfer path analysis predicting contributions to the vehicle interior noise for different excitations from the same sound source

摘要

For a quantitative ranking of contributions from several sources via different transfer paths to a response, in this example the vehicle interior sound, Transfer Path Analysis is applied. The method used in this experiment is the Operational Transfer Path Analysis, which calculates linearized transfer functions between selected source and response channels using singular value decomposition. For the analysis, several multichannel measurements, containing synchronous data for structure- and air-borne sound, in different operating conditions were performed. The transfer functions calculated from an engine run-up measurement are used to analyze the contributions of the main sound sources over the dominant transfer paths to the vehicle interior noise. In addition, the excitation from the main source was altered while all other aspects of source and structure were kept the same. In this experiment the engine excitation was altered by changing parameters of the engine control unit. Using the calculated transfer functions, predictions of the vehicle interior noise for the altered excitations are evaluated. The resulting sound pressure level of the calculated vehicle interior sound is in accordance with the values from the original measurements.