中文摘要：

高速列车表面脉动压力是引起气动噪声的主要根源,研究车体表面脉动压力对噪声控制等方面有重要意义。采用大涡模拟（LES）仿真计算高速列车运行时头车和尾车外流场的脉动压力,利用二进正交db小波将脉动压力分解为能量互不重叠的正交频带,并分析脉动压力在各频带上的能量分布规律。数值仿真结果表明：列车表面脉动压力由平均压力和在平均压力附近上下波动的脉动部分组成,脉动压力在全频带均有分布,且主要集中在低频区域;随着列车运行速度的提高,车体表面脉动压力幅值迅速增大,主要能量向高频区域移动;头车、尾车脉动压力变化趋势相似,且头车脉动压力大于尾车脉动压力。

英文摘要：

Fluctuation pressure on the surface of high speed train is the main source causing aerodynamic noise. Hence, it becomes very important to research the fluctuation pressure for controlling the aerodynamic noise etc. Large Eddy Simulation （LES） method was adopted to simulate the fluctuation pressure on a certain type of CRH high speed train. The selected targets of this simulation were train head and train tail. The fluctuation pressure from simulation was decomposed into several orthogonal frequency bands by using the discrete dyadic db wavelet and the distribution rule of the energy of eaeh frequency band was studied. The simulation results show that fluctuation pressure on the surface of train head and train tail is composed of the average pressure and the fluctuation proportion that oscillates around the average pressure; fluctuation pressure exists among all the frequency bands and the major energy concentrates in the low frequency domain; with the increase of train speed, amplitudes of fluctuation pressure grow heavily and the major energy has the tendency to move to high frequency domain. It is similar for the change rules of fluctuation pressure on both train head and train tail. In addition, the fluctuation on train head is greater than that on the train tail.