IDENTIFICATION AND SUPPRESSION OF NOISE SOURCES AROUND HIGH SPEED TRAINS

Aerodynamic noise would become a significant limiting factor as the running speed of high speed trains increases, and should be taken into consideration during the design of high speed trains. In the present work, the Nonlinear Acoustics Solver (NLAS) has been adopted to investigate the aerodynamic noise of high speed trains. The region around the streamlined head of the leading car and the trailing car, the bogie region, the upstream zone and the wake zone are discussed and the distribution characteristics of aerodynamic noise sources around a high speed train is exhibited. The acoustic characteristics of the streamlined head could be contaminated due to the unreasonable arrangement of cab windows or cowcatchers. As a result, different designs of cab windows and cowcatchers are investigated in this paper and advice on low noise design is given. Based on the above analysis, a new design of the streamlined head is proposed. Numerical results reveal that the noise level of the new streamline has been greatly suppressed. The analysis would aid in identification of noise sources around high speed trains and design of high speed trains with low noise.