Research on aerodynamic design and anti-crosswind characteristics of asymmetric wing span high-speed train aerodynamic lift wing

This study addresses the problems of excessive lateral rolling moments and potential train overturning caused by crosswinds and train overtaking, through the control of aerodynamic lift wings (ALWs) installed on the roofs of high-speed trains. The aerodynamic lift mechanism and operating principles of the ALW are analyzed, and a design scheme is proposed for an aerodynamic lift wing with an asymmetric wingspan (AWALW), suitable for operating speeds of 400 km/h and above. Results show that the lift, drag, and rolling moment generated by the AWALW exhibit a linear relationship with the span length of its asymmetric design. As the span length on one side decreases, the rolling moment increases linearly, accompanied by a significant lift enhancement. When the AWALW operates with an asymmetric span of 1600 mm, the aerodynamic lift coefficient of the lead car reaches 0.228, and the rolling moment reaches 6.94 kN∙m at 400 km/h. Under crosswind conditions, the flow patterns and vortex structures on the windward and leeward sides of trains equipped with AWALWs exhibit clear asymmetry. On the windward side, the tip vortices of each wing interact, while on the leeward side, they extend outward to form vortex tube structures. When high-speed trains equipped with AWALWs operate at 400 km/h, and the crosswind direction angle is below 45°, the resulting lateral rolling moment is reduced compared to the baseline train, indicating improved lateral stability. However, when the crosswind direction angle increases to between 45° and 90°, the rolling moment becomes comparable to that of the baseline, mainly due to the decreased aerodynamic efficiency of the AWALW under higher wind angles.