导流罩对受电弓气动噪声影响的风洞试验研究

受电弓是高速列车顶部最主要的气动噪声源,合理的导流罩设计是降低受电弓气动噪声的重要方法。通过声学风洞试验的方法,研究缩比模型导流罩对高速列车受电弓气动噪声的影响,采用远场麦克风及声阵列,给出了风速范围为200～250 km·h~(-1)时的升弓、降弓状态下,受电弓和加装导流罩的远场气动噪声频谱、主要噪声源位置、强度和对应频带范围。研究表明,受电弓气动噪声为宽频带噪声,中频噪声源位于受电弓区域后部近车体位置,中高频、高频噪声源对应弓头和支座区域;升弓状态下,导流罩增大了弓头区域的气动噪声能量,在降弓状态下,导流罩减小了弓头和支座的噪声水平。

Wind tunnel experimental research on the effect of guide cover on aerodynamic noise of pantograph

The pantograph is the main aerodynamic noise source at the top of high-speed trains, and the key to reduce the pantograph aerodynamic noise is to properly design the pantograph guide cover. By using aero-acoustic wind tunnel test method, the influence of the guide cover on the aerodynamic noise of high speed train''s pantograph is studied at the speed of 200~250 km·h^-1. Received by far field microphones and the array, the noise spectrum, dominant noise source positions, the intensity and the frequency ranges are given under the pantograph lifted and folded conditions. The study indicates that the pantograph aerodynamic noise is broadband noise; the middle frequency noise sources locate at the rear of the pantograph area near train body; the pantograph head and supporter correspond to the positions of middle and high frequency noise sources. In pantograph lifted condition, the aerodynamic noise of the pantograph head is increased by the guide cover. However, in the pantograph folded condition, the aerodynamic noise at the pantograph head and supporter is decreased by the guide cover. The results show that:the proper design of the cover can reduce the aerodynamic noise in folded condition, and avoid increasing the aerodynamic noise at the pantograph head in lifted condition.