Monitoring and Analysis of Acoustic Characteristics of Interior Noise of a High-speed Train Running in Low Temperature Environment

Abstract

In this study, the interior noise at the end of a high-speed train coach were monitored and analysed under a working condition of 250 km/h in an extreme low temperature environment (between -28 ℃ and -30 ℃). Meanwhile, the vibration levels of the floor, panel, ceiling and bogie systems were also measured. Subsequently, these monitoring data was used to conduct an interior cavity acoustic modal simulation. The simulation results confirmed the characteristics of the noise distribution and the noise generation mechanism. Accordingly, countermeasures against this kind of interior noise were proposed and then it is implemented to reduce the interior noise at the end of the high-speed train coach. The effectiveness of the method in noise reduction was verified. Based on the verification results, a new type of floor structure using a metal damper was designed to attenuate vibration energy at 110Hz. The purpose is to effectively control abnormal noise caused by the acoustic-structure coupling. The present results indicate that the noise and vibration of the high-speed train using a new type of floor structure is significantly lower than the original train without this damping structure. This design will efficiently improve the low frequency vibration as trains pass through sleepers.