Research Advances on Aerodynamic Noise of High-Speed Trains

With the increase in operating speed, aerodynamic noise become the technical bottleneck restricting the development of the high-speed railway. This paper reviews the research on the aerodynamic noise of high-speed trains from the perspectives of prediction, mechanism analysis and noise control methods. In terms of prediction methods, the research on the aerodynamic noise of high-speed trains is mainly based on static and dynamic trains, and the wind tunnel test and the field tests are the typical corresponding experimental methods, respectively. Based on the flow-filed simulation, the FW-H equation, the APE equation, and other calculation methods are mainly applied to predict the far and near field noise accurately in simulation. The regions with severe flow separation, such as bogies and pantographs, etc., are identified as the primary noise sources. In terms of mechanism analysis, unsteady flow statistics are helpful in identifying sound sources empirically. Furthermore, the sound source term based on the aerodynamic noise calculation methods can theoretically characterize the sound source characteristics. The reduced-order method, coherence analysis and other statistical analysis methods are applied to clarify the relationship between the flow field. The aerodynamic noise can be optimized by passive control methods, such as the bogie cavity fairing, and active control methods, such as the airflow jet. The noise control methods can be further optimized combined with parametric modeling, genetic algorithm and other methods, which deserve more attention.