Reducing Method of Aerodynamic Noise from High Speed Pantograph

The aerodynamic noise from pantograph is one of the important external noise source of a high speed train as Shinkansen. The external noises of testing trains were measured using a linear-array type directional microphon and a full-scale pantograph was tested in a low noise wind tunnel. It is shown that the intensity of the pantograph aerodynamic noise is proportional to the 6th power of velocity and severe at the near place to the head of a train. A frequency analysis shows that the Aeolian tones from the bow and the oblique pipe of pantograph give main contributions. It is confirmed that an appropriate irregularity of diameter of cylinder or an air gap in the section of the bow are effective for reducing the Aeolian tones.