Numerical and experimental study on the aerodynamic noise characteristics of 600-km/h high-speed maglev trains

High-speed maglev trains represent a new mode of transportation;however,their 600-km/h travelling speed causes serious aerodynamic noise problems,with very little research on the aerodynamic noise of such trains.To clarify the aerodynamic noise source and radiation characteristics of high-speed maglev trains,both large eddy simulations and wind tunnel experiments with a 1:8 scale threetrain model were conducted to obtain the aerodynamic noise source spectrum and spatial distribution characteristics of the maglev train at different speeds;the contribution of the dipole noise source was also analysed.The results revealed that the train shape has a significant impact on the frequency distribution of the far-field aerodynamic noise below 1 kHz,with the highest sound power concentrated on the train head,especially in the areas around the track joint and streamlined sections.The surface dipole sound source energy increases linearly with speed and is mainly distributed at the bottom of the train head and tail train body.A short-streamlined train exhibited the highest ratio,especially in the trailing edge area,up to 1.42×1011 dB.The far-field sound pressure level of the short-streamlined maglev train is significantly higher,with a maximum difference of about 10 dBA.The distribution pattern of the far-field sound pressure level is influenced by the train type,reflected in the tail train and wake area.Different frequency intervals have different relationships between the acoustic pressure level and frequency;long-streamlined models may enhance broadband features in the sound field distribution of high-speed maglev trains.These findings could be used to guide the aero-acoustic design of maglev trains with a designed speed of 600 km/h.