Research On Aerodynamic Noise Control Technology Of Head Car Of High Speed Train

Considering that the main contribution of high-speed train noise is aerodynamic noise,numerical calculation of aerodynamic noise for Fu Xing EMU train is carried out in this paper,including the establishment of simplified geometric model,numerical calculation of flow field,extraction of pulsating pressure,conversion of sound source and calculation of sound propagation.According to the mechanism of pneumatic noise,combined with the calculation results of flow field and acoustic field,preliminary determine the high-speed train car head of aerodynamic noise sources mainly exist in the head below the car cowcatcher front edges area as well as the first car I and II a bogie area and bogie tank apron edge edges,has obvious characteristics of broadband,but mainly concentrated in the low frequency noise energy section,The directivity of the sound source to both sides and rear regions is more prominent.In flow field numerical calculation is different from the past to pneumatic acoustics of numerical calculation,this paper USES the local coordinate system the way of the rotation of the wheel to regional,more real reflect the bogie area flow field condition,wheel rotation before and after processing of comparison and analysis of flow field calculation result and the sound source,found wheel bogie in the rotating flow field after processing area of vortex distribution is more chaotic,The degree of turbulence is more intense,and the pressure fluctuation at different positions is also different from that before rotation.According to the noise control theory,noise control schemes are proposed for the main aerodynamic noise source location of the baffle front and bogie area respectively.For the location of the baffle front,the method of edge removal optimization is adopted,and for the bogie area,the method of noise reduction optimization is adopted,which includes the skirt plate and the back wall with sound absorption treatment.By comparing and analyzing the noise data before and after the structure optimization,the noise level of the baffle and bogie after the optimization is reduced in the position of the sound source,and the radiation value of the aerodynamic noise in the far field is decreased more obviously,and the noise reduction effect is good.After the whole bag apron optimized design in the bogie hold because of the wall will make high frequency acoustic reflection has the trend of increase,the whole package apron internal acoustic noise reduction processing,the lining of paste sound-absorbing plate,after processing of bogie tank almost no reflections,the influence of internal so noise level of the sound absorption treatment hold down obviously,achieve the desired effect,It also proves the feasibility of all-inclusive skirt board in the future.