地铁车辆空调风道内气动噪声数值仿真分析

Simulation Analysis of the Value of Aerodynamic Noise in the Air Conditioning Duct of Metro Cars

为了研究地铁车辆空调系统辐射噪声的变化规律,提升地铁车内声品质,以空调机组和送风风道的组合模型为基础,采用有限体积法和基于声学有限元的自动匹配层技术,构建设计风量条件下的计算域网格。通过建立地铁列车空调风道系统气动噪声的仿真模型,分析了风道的流场、气动噪声源性能以及辐射噪声性能,研究了风道内流场分布特征及其声学规律。仿真结果表明:风道内用于调节送风均匀性的孔板,同时具有消声作用,可进一步降低风道内流场扰动引起的噪声;对于空调机组的噪声,风道具有较大的降噪效果;在客室和司机室连接处,贯通道处声压较高,需要采取有针对性的减振降噪措施。文章对地铁车辆空调送风风道内气动噪声特性的研究为地铁车型车内声学优化设计提供了参考。

To study the change law of the radiation noise of the air conditioning system of a metro car and improve the sound quality in a metro train,the model combining the air conditioning unit and the air delivery duct is taken as the basis.The finite volume method and the automatic matching layer technology based on the acoustic finite elements are adopted to build the computational domain grid in the design air quantity condition.The simulation model of aerodynamic noise in the air conditioning duct of a metro train is built to analyze the flow filled in the air duct,the performance of the aerodynamic noise source,and the performance of radiation noise,and to study the characteristics of flow field distribution in the air duct and its acoustic law.The simulation result shows that the pore plate to adjust the air delivery evenness in the air duct also has the function of a muffler that can further reduce the noise caused by disturbance of the flow field in the air duct.The air duct has a better noise-reducing effect on the noise of the air conditioning unit.In the joint of the passenger compartment and the driver's cab,the sound pressure in the through channel is higher and needs targeted vibration and noise reduction measures.The study on the characteristics of aerodynamic noise in the air conditioning duct of a metro car in this article provides a reference for the in-car acoustic optimization design of metro trains.