高速列车气动噪声数值仿真

Research on Numerical Simulation of Aerodynamic Noise for High-Speed Train

建立了高速列车组包括头车、中间车、尾车及外部空间在内的气动噪声计算物理模型,从声学理论出发,结合列车实际运行的边界条件,运用以稳态结果作为初始值进行瞬态计算,预测了高速列车气动噪声,并对采用直接瞬态法计算气动噪声的可行性进行了分析计算.研究结果表明气动噪声分布于很宽的频带内,无明显的主频,属于宽频噪声.在低频中气动噪声能量较大,在高频上能量较小.以稳态结果作为初始值的计算方法能准确地预测高速列车的气动噪声特性,同时节省计算时间;直接瞬态计算的气动噪声结果没有明显的规律,反映不出列车的气动噪声特性.

A three-dimension computational fluid dynamics model with a head nose-coach, a middle coach and a tail nose-coach is constructed, and the boundary condition is exerted according to the practical case. The transient fluid dynamic computations are performed using the steady results as a original values, the near-field aerodynamic noises are achieved, and the feasibility of using the direct transient method is analyzed by per- forming a direct transient computation. The results show that the aerodynamic noise is a broadband noise in a wide frequency range without a main frequency. The noise energy is higher in low frequency and lower in high frequency. The method using the steady results as a initial value can exactly forecast the aerodynamic noise, while the results computed by the direct transient method have not a correct tendency, and can not be used to evaluate the aerodynamic noise characteristics.