Study on the aerodynamic performance and noise of windshield area in high-speed trains at a frequency of 38 hz

The noise level of a high-speed train is a crucial indicator of its operational quality. A significant low-frequency interior noise, referred to as '38 Hz' in this context, has been detected during the operation of high-speed trains. This notable noise primarily occurs in the train attendant's cabin near the windshield area. In this study, we conducted a comprehensive full-scale test to investigate the preliminary cause behind this significant '38 Hz' noise. Our investigation reveals that it is associated with aerodynamic noise originating from the windshield area. To identify the root cause of this '38 Hz' noise in the windshield area, we established a computational fluid dynamics (CFD) based model for aerodynamic noise analysis. The causes were found to be related to both the size and opening of the windshield cavity. Simulation results demonstrate that closing the upper opening significantly reduces the volume of '38 Hz' noise compared to the original outer windshield structure design. We verified and validated these findings through an extensive full-scale test, which showed that by implementing our proposed modified windshield structure, there was approximately 7 dB reduction in significant '38 Hz' noise observed within the train attendant's cabin near the windshield area.