仿生菱形表面织构对高速列车摩擦噪声的影响

为了降低高速列车运行时的空气摩擦噪声, 仿生鲨鱼皮的表面织构, 在高速列车车厢气固界面设计了菱形表面织构, 建立了噪声分析模型, 采用非结构化混合网格和k-ε模型求解可压缩N-S方程, 基于宽频噪声源模型求解噪声分布。计算结果表明: 在菱形织构内部产生涡流, 使噪声明显降低, 同时车厢表面的噪声分布也发生变化; 列车产生的空气摩擦噪声随着运行速度的增大而增大, 与光滑表面相比, 优化对角线比的菱形织构的摩擦噪声的最大降幅为24dB, 优化深边比的降幅为20dB。

Effect of bionic rhombic surface texture on frictional noise of high-speed train

In order to reduce the frictional noise of gas-solid interface for running high-speed train, a noise analysis model of gas-solid interface was established by using the rhombic surface texture to mimic the surface texture of jaws shin. The compressible N-S equation was solved by using unstructured hybrid grid and k-ε model, and the noise distribution was obtained based on broadband noise source. Numerical result demonstrates that the noise significantly reduces as result of eddy current in the rhombic structure, and the corresponding noise distribution also changes. The air frictional noise of running train increases with the increase of the speed. Compared with the smooth surface, the maximum reducing value of noise intensity for the surface texture with optimal diagonal ratio is 24 dB and the value with optimal depth to side ratio is 20 dB.