Noise reduction of high-speed train pantograph cavity based on the combination of active jet and vortex generator

With the continuous increase in operating speeds of high-speed trains, aerodynamic noise generation in the pantograph cavity region has emerged as a critical challenge in railway engineering. To address this issue, this study proposes an innovative hybrid flow control strategy combining an active leading-edge jet with vortex generators at the cavity base. Through synchronized implementation of large eddy simulation (LES) for turbulent flow resolution and the Ffowcs-Williams-Hawkings (FW-H) acoustic analogy for noise propagation modeling, this paper systematically investigated the noise suppression mechanisms induced by jet parameter optimization. Numerical results demonstrate that this synergistic control approach achieves broadband noise reduction across monitoring positions. At 400 km/h operation speed, the proposed configuration yields average sound pressure level (SPL) reductions of 2.96 dB, 3.05 dB, and 3.00 dB at 7.5 m, 12.5 m, and 25 m observation points, respectively. Furthermore, parametric studies reveal that jet orifice contraction angle optimization plays a important role, with the 15° configuration exhibiting maximum noise reduction through enhanced flow attachment and vortex shedding frequency modulation. This research provides theoretical foundations and technical references for pantograph aerodynamic noise control systems of high-speed trains.