Road Test Measurement and SEA Model Correlation of Dominant Vehicle Wind Noise Transfer Paths

In order to effectively use CAE to meet wind noise NVH targets, it is important to understand the main wind noise transfer paths. Testing confirmation of these paths by means of acoustic wind tunnel test is expensive and not always available. An on-road test procedure including a “windowing” method (using barriers) was developed to measure wind noise contribution at important higher frequencies through the main transfer paths, which were shown by test to be the glasses at a typical operating condition in which wind noise was dominant. The test data was used to correlate a full-vehicle SEA (Statistical Energy Analysis) model that placed emphasis on the glass properties, main noise transfer paths, and interior acoustic spaces while simplifying all other transmission paths. A method for generating wind noise loads was developed using measured glass vibration data, exterior pressure data, and interior acoustic data. The individual glass paths were correlated and a baseline model was developed including the noise contribution of all glass paths and a lumped non-glass flanking path. Design studies of the glass properties were performed, especially to explore the overall acoustic performance potential of laminated glasses, individually and in combination, which have potential to reduce vehicle weight. These results and recommendations of how this technique and baseline model can be extended to other vehicle body styles and conditions are presented.