Aerodynamic Noise Reduction in Pantographs by Shape-smoothing of the Panhead and Its Support and by Use of Porous Material in Surface Coverings

Abstract

To reduce the aerodynamic noise generated by a pantograph, which is one of the dominant noise sources in high speed trains, the authors have proposed a set of noise reduction techniques, namely, shape-optimization of the panhead, relaxation of aerodynamic interference between the panhead and the articulated frame, and the use of porous material for surface covering. To evaluate the total noise reduction effect of these techniques, they were applied to a prototype pantograph which was tested in a wind tunnel. Test results showed that the prototype pantograph lowered the noise level from the current low-noise pantograph by about 4dB. Furthermore, they also confirmed that the prototype pantograph had sufficient aerodynamic stability against change of attack angle.