高速列车气动噪声源特性研究

Research on Characteristics of Aerodynamic Noise Source for High-speed Train

本文建立包括头车、尾车、中间车、受电弓、6个转向架在内的CRH3高速列车整车三维绕流流动的物理数学模型,用Fluent软件内大涡模型数值计算外部瞬态流场,得到时域Lighthill声源项,对时域声源项进行傅利叶变换得到频域声源项,用有限元-无限元法计算高速列车车头及转向架、受电弓、车尾及转向架附近的气动噪声,得到高速列车主要气动噪声源的声压分布及特点。计算结果表明:受电弓弓头部附近气动噪声最大,而且具有更多高频噪声,300km/h速度运行时其总声压级为156.3dB,受电弓底座也具有很高的声压级,并且具有较多的低频噪声;在车头及第一个转向架附近,转向架区域噪声明显高于车头鼻尖处,其总声压级分别为135.3dB和129.7dB;在车尾及最后一个转向架附近,车尾部噪声大于转向架区域噪声;总气动噪声声压级按受电弓滑板、受电弓底座、车尾部、第一个转向架、车头部逐次降低。通过与现有文献的对比分析,证明了本文计算结果的正确性。

A three‐dimension computational fluid dynamics model including a head nose‐coach , a middle coach , a tail nose‐coach ,a pantograph and 6 bogies was built . The exterior transient fluid field was calculated using the large eddy simulation（LES） from Fluent software to obtain the time‐domain Lighthill acoustic source term . The time‐domain acoustic source term was transformed into frequency‐domain acoustic source term through Fourier transformation . A finite element‐infinite element model was used to calculate the aerodynamic noise a‐round the head nose‐coach and its bogie , the pantograph , the tail nose‐coach and its bogie , to gain the acous‐tic pressure distribution and the characteristics of the aerodynamic noise source of a high speed train . The cal‐culation results showed that maximum aerodynamic noise existed at the pantograph head slide plate where there was more high frequency noise .At the speed of 300 km/h ,the maximal sound pressure level（SPL） reached 156.3 dB .The pantograph base had high SPL as well where there was more low‐frequency noise .With respect to the head nose‐coach and the first bogie , the noise at the bogie was significantly higher than that at the nose position of head coach , with the maximal SPL reaching 135.3 dB and 129.7 dB respectively . On the contrary , the noise at the nose position of the end coachwas higher than that at last bogie . The total SPL of the aerody‐namic noise was progressively declining in the sequence of the pantograph head slide plate , pantograph base , the nose position of the end coach , the first bogie and the nose position of the head coach . T he validity of thenbsp;calculation results presented in this paper has been confirmed by a comparative analysis with existing literature .