Flow control solutions for safe operation of high-speed trains in crosswinds: A study of leeward side deflector wing configurations

Maintaining the aerodynamic steadiness for high-speed trains is of paramount importance, particularly in the scenario of operating in crosswinds. In light of this, a novel configuration of the deflector wing on the surface of the train's leeward side is designed in this work, while the optimized impacts on the nearby flow field structures for the operational train induced by the deflector wing, as well as its aerodynamic performance, are also investigated. Against the original train, the findings indicate that the high-speed train equipped with the leeward side deflector wing significantly reduces the side force its suffers and rolling moment under crosswind scenarios, especially resulting in a 17.85% decrease in CFy and a 22.60% decrease in CMx at position D, respectively; In addition, the further analysis reveals that the formation and development of vortex structures in the vicinity of the train are affected by the configured deflector wing so as to reduce the high negative pressure affecting on the train's leeward side surface and to balance the differential pressure on the train's sides; In terms of the turbulence kinetic energy of the vortex formated around the train, the deflector wing of the train suppresses the vortex's entangling and acceleration to weaken the concentrated energy of the vortices and flutuation of the airflow around the train surface, thus leading to an improvement of the aerodynamic stability of high-speed train operating in crosswinds.