Enhancing Effect of Leeward Side Deflector on High-Speed Trains Aerodynamic Performance Under Crosswinds

To enhance the aerodynamic performance of high-speed trains in crosswinds, the aerodynamic forces and flow structures of the high-speed train with the deflector are investigated in this work, while the influence of deflectors on the train’s leeward side in various positions on the train’s aerodynamic performance is also compared. The results show that the deflector configured on the leeward side of the train has a notable effect on reducing the rolling moment coefficient (CMx), as compared to the case without a deflector, resulting in a decrement of 4.39%, 11.66%, and 19.80% at position A, position B and position C, respectively. The flow structures around the train further reveal that the deflector plate inhibits the winding and acceleration of vortexes formed in the leeward side of the train and weakens the concentrated as well as strong energy of the vortices, compared to the case without deflector, and therefore leading to an improvement in the train's aerodynamic performance in crosswind environments.