Numerical Analysis of Aerodynamic Noise of Motor Car Bogie for High-Speed Trains

In order to study the aerodynamic noise characteristics of motor car bogie in high-speed trains, an aerodynamic model of motor car bogie was established, a preliminary study on the aerodynamic noise source of the motor car bogie was made using the steady-state RNG k- turbulence model and the broadband noise source model, and the far-field aerodynamic noise was analyzed by combined use of the transient-state large eddy simulation (LES) and Lighthill' s acoustic analogue theory. The results show that the wheel set, bogie frame, traction motor-1, bolster, vertical shock absorber, anti-rolling torsion bar and other protruding parts on the windward side are the aerodynamic noise source of the bogie. Among them, bogie frame has the largest contribution to the total far-field aerodynamic noise of the bogie, the wheel set and anti-rolling torsion bar have the secondary contribution, and the vertical shock absorber and bolster have the third contribution amount. Compared to the above components, the traction motor-1, traction motor-2, air spring and lateral shock absorber have less contribution to the total noise. In addition, the far-field noise of the motor car bogie is a broadband noise, characterized by attenuation, amplitude and aerodynamic noise directivity. The main energy of the noise in the low frequency band is concentrated at the centre frequencies 25 and 50 Hz, and the power spectral density distribution does not change with the train speed.