Interior Noise Reduction Method of Pantograph Areas for High-speed Trains Based on Active Jet

The interior noise caused by the pantograph area is greater than that caused by other areas, and the impact of this pantograph area becomes more significant as the speed of high-speed trains increases, especially above 350 km/h. This study proposes an active jet method for pantograph cavities to control noise at the source. First, a predictive model for the interior noise of pantograph carriages was established by jointly adopting large eddy simulation-statistical energy analysis methods. Then, numerical simulations were conducted to determine the external noise sources and interior sound pressure level at different speeds (300, 350, 400, and 450 km/h). Finally, active jets at different speeds (97.2, 111.1, 125, and 140 m/s) were used to analyze the reduction in interior noise. Results showed that the active jet method decreased the average overall sound pressure level of the acoustic cavity in the horizontal plane. When the train speed reached 450 km/h, the optimal reduction in interior noise was approximately 7.5 dB in the horizontal plane for both the standing and sitting postures. The proposed method can efficiently reduce interior noise in the pantograph area.