圆坑织构高速列车气固界面的摩擦噪声分析

Frictional noise analysis of gas-solid interface with circular dents for high-speed train

以Prandtl边界层理论和摩擦噪声理论为基础,建立了高速列车车厢气固界面的噪声模型,分析了边界层内部的压力场、速度场和噪声分布情况。仿生猎隼表面织构,以表面织构产生微小的涡流场减小空气摩擦阻力,并设计了车厢表面的圆坑织构,分析了圆坑织构参数对摩擦噪声分布的影响。分析结果表明:优化织构的深径比、面积比与织构的拓扑结构可取得显著的降噪效果,与光滑界面相比,优化深径比的织构的摩擦噪声的最大降幅达到11dB,其他织构在一定高度能降低4～5dB。

Based on Prandtl boundary theory and frictional noise theory, a noise model of gas-solid interface of high-speed train was established, and the fields of pressure, rate and noise intensity were examined. The surface texture with circular dents for railway carriage was designed by mimicking eagle feather to yield micro whirl field resulting in less frictional air drag, and the influence of textural parameters on the distribution of noise intensity was studied. Simulation result demonstrates that the optimal depth-radius ratio, area ratio and topology type of surface texture can remarkably reduce frictional noise. Compared with smooth surface, the maximum reducing value of noise intensity for the surface texture with optimal depth radius ratio is 11 dB, and the maximum reducing values of noise intensities for other optimal surface textures are 4-5 dB. 20 figs, 14 refs.