On reducing high-speed train slipstream using vortex generators
Shuai Han, Nanshen Xiang, Fengyi Huang, Ao Xu, Jie Zhang
Abstract
The slipstream generated by high-speed trains presents significant challenges to the safety and stability of trackside infrastructure. This study explores the impact of vortex generators (VGs) on the wake evolution of a high-speed train as a passive control strategy to mitigate slipstream effects. Three VGs with varying heights are employed, and their effectiveness in reducing slipstream velocity is evaluated using improved delayed detached eddy simulations. The numerical model is validated against experimental data, and simulation results reveal that the height of the vortex generators plays a crucial role in reducing slipstream velocity. With VGs of 0.05H height, the mean and maximum slipstream velocities decrease by approximately 3% and 10%, respectively. As the VG height increases to 0.15H, these reductions become more pronounced, reaching approximately 16% and 20% for the mean and maximum velocities, respectively. The mechanism underlying slipstream suppression is analyzed, showing that higher VGs generate additional vortices, which enhance the suppression effect. Furthermore, the increase in vortex generator height leads to a more pronounced suppression of turbulent kinetic energy within the wake region and a more substantial attenuation of trailing vortices, which significantly enhances the aerodynamic performance of the train. The intensity of vortices is reduced progressively as VG height increases from 0.05H to 0.15H, with reductions of approximately 7%, 19%, and 26%. The proposed method provides a straightforward yet effective approach to wake control, offering significant benefits for slipstream mitigation.