Using leeward air-blowing to alleviate the aerodynamic lateral impact of trains at diverse yaw angles

Abstract

The safety risks of high-speed trains in crosswind environments escalate with increasing train speeds. The present study employs the improved delayed detached eddy simulation method based on the shear stress transport k–ω turbulence model to evaluate an active control method targeting the reduction of lateral forces acting on the train. The effects of air blowing strategy on the leeward side of the train are examined considering different yaw angles and blowing speeds. The findings reveal that the active air blowing, mixed with the flow laterally downstream the train roof, induces the increase in the local turbulence and alters the surface pressure distribution. Within the investigated range of yaw angles, the active air blowing yields a lateral force reduction ranging from 1.0% to 8.8%. Varying the blowing speed can further decrease the lateral force of the entire train by 5.9% and 0.8% at yaw angles of 15° and 75°, respectively. The power invested in active blowing demonstrates maximum returns at a yaw angle near 45° while diminishing with increasing blowing speed.