Research on noise reduction method in high-speed train carriages based on active jet flow

To address the aerodynamic noise induced by higher speeds, the acoustic pressure in the pantograph region and the resulting interior noise of a 400 km/h high-speed train were investigated. The noise reduction effect of active jet flow on the pantograph cabin was explored. The results show that the acoustic pressure in the pantograph region exhibits distinct high-frequency characteristics, with dominant frequencies distributed between 1000 and 1600 Hz, primarily concentrated around insulators and the upstream cavity. After the application of active jet control, the acoustic pressure was significantly reduced in the frequency range of 20 – 2500 Hz. Power input to the pantograph cabin acoustic cavities originates primarily from adjacent cavities and panels, with frequencies distributed between 20 and 1600 Hz. A frequency jump occurs at 1250 Hz due to the coincidence frequency effect in single-layer panels. The interior noise directly below the pantograph was reduced by 3.7 dB, with the most significant reduction of 3.5 dB observed in the acoustic cavity most sensitive to human hearing. The front passenger cabin cavity achieved an average noise reduction of 3.3 dB. These findings provide references for future interior noise reduction in high-speed trains.