Research On Aerodynamic Noise Model Of High Speed Train

With the progress of science and technology,the speed of high-speed trains is gradually increasing.When the train speed reaches a certain height,aerodynamic noise becomes the main noise source.It is of great significance to study the mechanism of aerodynamic noise generation of high-speed trains and control the noise effectively.In this paper,a wind tunnel simulation test is carried out to study the spectral characteristics of aerodynamic noise on high-speed trains and its relationship with the speed.Acoustic wind tunnel model test is fast,convenient and repeatable.Firstly,the wind tunnel test system of high-speed train model is built based on similarity theory.Then the near field measurement of aerodynamic noise outside high-speed train is carried out by using the test system.The sound pressure signal is Fourier transform and the spectrum distribution of aerodynamic noise intensity of high-speed train is obtained by cross spectrum method.The simulation model of high-speed train is established by means of simulation,and the aerodynamic noise characteristics of high-speed train are simulated.Based on the analysis of test and simulation results,it is found that the sound intensity of the external aerodynamic noise of the train decreases with the increase of frequency,and the peak of sound intensity appears in the range of 100-500 hz frequency,that is,the aerodynamic noise energy is mainly concentrated in the low-frequency region.Further simulation results show that the aerodynamic noise of high-speed trains increases with the increase of speed.The aerodynamic noise of high-speed trains grows fastest from 200km/h to 300km/h,with an increase of 20.8%.After 400km/h,the aerodynamic noise of high-speed trains slows down.