高速列车转向架部位气动噪声数值模拟及降噪研究

Aerodynamic noise numerical simulation and noise reduction of high-speed train bogie section

基于Lighthill声学理论,采用三维、LES大涡模拟和FW-H声学模型对高速列车转向架部位气动噪声进行数值模拟,并提出降噪改进意见。研究结果表明:转向架部位气动噪声在很宽的频带内存在,无明显的主频率,是一种宽频噪声;各监测点气动噪声频谱在低频时幅值较大,随着频率的升高,幅值下降,1/3倍频程A声压级主要集中在315～1 250 Hz频率范围内;当来流速度一定时,距离气动噪声源越远,声压级幅值和总声压级越小;在列车转向架部位设置裙板后,运行速度为300 km/h时,车外声压级幅值较无裙板时有所减小,平均降幅约为8%,总声压级平均降幅1.3 dBA;适当增加裙板面积后,声压级幅值平均降幅达到12%,总声压级平均降幅2.08dBA,降噪效果较明显。

In order to decrease the aerodynamic noise of train bogie section,three-dimensional,large eddy simulation and FW-H acoustic model were adopted to simulate the aerodynamic noise outside high-speed train bogie section based on Lighthill acoustic theory,and noise reduction advice was proposed.The results show that the aerodynamic noise is a kind of wide frequency noise which exits in wide frequency band without obvious main frequency.The acoustic pressure amplitude of every test point is great at low frequency,decreasing with the increase of frequency,and the acoustic pressure level within 1/3 octave band frequency ranges from 315 Hz to 1 250 Hz.Given a certain incoming wind speed,the total acoustic pressure level is lower when the test point is farther from the noise source.Once aprons are set in bogie sections,acoustic pressure amplitude and total acoustic pressure level of each point reduce compared with that without apron,respectively with an average reduction of about 8% and 1.3 dBA at the speed of 300 km/h.Besides,the average reduction will come to 12% and 2.08 dBA when the apron area increases properly,making noise reduction more effective apparently.