Wavenumber-frequency Analysis of Surface Pressure Fluctuations for Prediction of Interior Noise of High-speed Train Due to Wind Noise

Abstract

Wind noise in road vehicles is being made much quieter to satisfy customers' demands for comfortable driving environments. The interaction between outside flows and exterior surfaces at the front and sides of a vehicle forms a strong swirling fluid structure called A-pillar vortex which is one of the most crucial wind noise sources. The geometrical characteristics of the A-pillar can determine the size or strength of the vortex structure. It is tremendously time-intensive and costly to change the shape of the A-pillar if it cannot be modified in the early development stage. For early determination of its shape, a reliable numerical methodology to predict vehicle interior noise due to the A-pillar vortex should be applied. This can be very challenging because the numerical method should simulate the complicated fluid behaviors as noise sources and the structural motions acting as transmission and propagation paths with acceptable precision. In this study, various numerical solvers are validated as the predictive tool of the interior transmitted noise in a simplified vehicle model. The solvers examined in the open benchmark study use various computational fluid and vibro-acoustic methods. It is shown that most of the software has prediction ability enough to industrial purposes.