可实现宽频隔声的全向通风铁路声屏障

针对现有铁路声屏障通风性能差和自重大的问题，提出新型铁路声屏障设计. 该结构是由螺旋通道和中空通路相互组合的超单元并联形成的，基于Fano共振机理实现螺旋通道和中空通路之间的耦合，能够对特定频带的声波能量实现高效阻隔，具有厚度薄、自重小、通风性能好等优点. 分析超单元结构对斜入射声波的隔离效果，对超单元结构进行参数优化分析，研究超单元数量对设计声屏障隔声性能的影响，对超单元结构进行实验验证. 研究结果表明，该结构可以对不同角度入射的声波实现宽频隔离；参数优化后的超单元结构可以有效控制轮轨噪声主频，已达到实际应用要求；超单元数量不会对声屏障的隔声性能产生影响；仿真与实验结果具有较高的一致性.

Omnidirectional ventilation railway sound barrier capable of realizing wide frequency sound insulation

A new railway sound barrier design was proposed aiming at the problems of poor ventilation performance and heavy weight of existing railway sound barriers. The structure was formed by a unit in which a spiral channel and a hollow channel were combined with each other in parallel. The coupling between the spiral channel and the hollow channel was realized based on the Fano resonance mechanism. The structure can effectively block the sound wave energy in a specific frequency band. This railway sound barrier had the advantages of thin thickness, small weight and good ventilation performance. The isolation effect of the meta unit structure on oblique incident sound waves was analyzed. The optimization analysis of the parameters of the meta unit structure was conducted, and the influence of the number of meta units on the sound insulation performance of the designed sound barrier was analyzed. The meta unit structure was verified by experiment. Results show that the structure can achieve wide frequency isolation of sound waves incident at different angles. The meta unit structure can effectively control the main frequency of wheel-rail noise after parameter optimization. Then the actual application requirements are met. The number of meta units will not affect the sound insulation performance of the sound barrier. The simulation results accorded with the experimental results.