On the active flow control in maglev train safety under crosswinds: Analysis of leeward suction and blowing action

The design speed of high-speed maglev trains is much higher than that of wheel-rail trains, and they will be subject to more operational safety threats under complex wind conditions. The present study uses the improved delayed detached eddy simulation method based on the shear stress transfer k–ω turbulence model to explore the effect of active flow control on the aerodynamic lateral force of a maglev train and examines the main aerodynamic performance differences caused by two active control forms (suction and blowing airflow), involving multiple active flow speeds. In the current scenario, blowing can reduce the lateral force coefficient of the head car by up to 15% while greatly increasing its transient instability, which can be attributed to direct and indirect changes in pressure distribution near the air slots and a larger range of the leeward surface. The suction is believed to suppress the downstream motion of the main vortex on the leeward side of the maglev train and weaken the turbulent kinetic energy of the wake, while the blowing effect reduces the dominance of the main vortex. The application of blowing is proved as an effective means of reducing the risk of operating a maglev train in a crosswind environment, while it requires a careful consideration of both train safety and energy efficiency.