基于展向波纹穿孔结构的受电弓杆件减阻降噪研究

Research on Drag and Noise Reduction of Pantograph Rods Based on Spanwise Corrugated Perforated Structure

地铁列车在隧道中行驶时,受电弓对气流产生扰动并形成涡旋脱落,从而产生明显的气动噪声。对λ/D=2、ω/D=0.48的弓头展向波纹结构模型进行波峰、波谷、波峰波谷耦合穿孔优化设计,通过流体计算软件FLUENT进行流场的稳态和瞬态计算求解。采用标准k-ε模型计算稳态流场,在此基础上通过大涡模拟计算瞬态流场。基于气动噪声混合计算方法,将瞬态流场计算结果通过积分插值映射到声学网格上,并计算获取气动噪声声源及传播过程。仿真计算结果表明:展向波纹穿孔结构模型较无穿孔模型有降低气动噪声的作用;展向波纹结构波峰波谷穿孔模型较单独的波峰、波谷穿孔模型的降噪性能较优;在远场R=1.18 m、2 m、5 m处,展向波纹波峰波谷穿孔模型的总声压级较波峰穿孔模型降低了0.51 dB、1.46 dB和1.43 dB,较波谷穿孔模型的总声压级降低了0.37 dB、1.21 dB和1.29 dB。

The pantograph is an important current receiving device on the top of the subway train. When the subway travels in the tunnel, the air flow is disturbed and vortex shedding is formed, resulting in obvious aerodynamic noise. This paper takes the spanwise corrugated structure model of bow head with λ/D=2, ω/D=0.48 as the basis, the wave crest, wave trough, wave crest and wave trough coupling perforation optimization design are carried out, and the steady-state and transient calculation of the flow field is carried out through the fluid calculation software FLUENT. The standard k-ε model is used to calculate the steady-state flow field, and on this basis, the transient flow field is calculated by large eddy simulation. Based on the aerodynamic noise hybrid calculation method, the transient flow field calculation results are mapped to the acoustic grid through integral interpolation, and the aerodynamic noise source and propagation process are obtained by calculation. The simulation results show that the spanwise corrugated perforated structure model has the effect of reducing aerodynamic noise compared with the non-perforated model;the spanwise corrugated structure crest and trough perforation model has better noise reduction performance than the single peak and trough perforation model;in the far field R= At 1.18 m, R=2 m, R=5 m, the total sound pressure level of the spanwise corrugated wave crest and trough perforation model is 0.51 dB, 1.46 dB, and 1.43 dB lower than that of the wave peak perforation model, which is lower than that of the trough perforation model 0.37 dB, 1.21 dB, 1.29 dB.