高速列车车辆连接部位气动噪声数值模拟及降噪研究

采用大涡模拟与声类比相结合的方法,对高速列车车辆连接部位不同尺寸参数时的气动噪声进行了数值模拟,并提出降噪改进方案。研究得到了高速列车以300km/h速度运行时车辆连接部位的气动噪声分布,结果表明:车辆连接部位气动噪声在很宽的频带内存在,是宽频噪声;各监测点气动噪声频谱在低频时幅值较大,随着频率的增大先增大后减小,1/3倍频程A声压级主要集中在315～1000Hz频率范围内;车辆连接部位不同尺寸参数中,气动噪声声压级幅值随着凹槽长度L和高度H的增大而有所增加;采用全风挡方案较无风挡时,有效避免气流在凹槽内剧烈扰动,气动噪声显著改善,声压级平均降幅约为9.4%,总声压级平均降幅4.27dBA;研究结果为低噪高速列车的初期研制设计提供科学依据。

Numerical simulation of aerodynamic noise and noise reduction of high-speed train connection section

Aerodynamic noise of high-speed train connection section with different parameters were simulated numerically adopting LES model companied with acoustic analogy and reducion improvement project was proposed.The aerodynamic noise distribution of high-speed train connection section at speed of 300km/h was obtained from the research,the results show that aerodynamic noise is a kind of wide frequency noise which exits in wide frequency band.The acoustic pressure amplitude of every test point is bigger at low frequency,increasing firstly then decreasing with the increase of frequency,and acoustic pressure level within 1/3 octave band frequency concentrates in the rage of 315-1000Hz;Among different parameters of train connection section,the acoustic pressure level amplitude increases with the increase of groove length and height;Compared with the project without windshield,the noise reduction effect of full windshield project is apparent,avoiding severe disturbance flow effectively,the average acoustic pressure level reductive amplitude is 9.4% and the average total acoustic pressure level reductive amplitude is 4.27dBA.All these researches provide scientific foundation to the initial design of high-speed train with low noise.