Mitigation of crosswind effects on high-speed trains using vortex generators

Abstract

Vortex generators can enhance the operational safety of high-speed trains and offer effective anti-rolling performance. This paper investigates the influence of vortex generator installation angles on the aerodynamic characteristics of trains. The Improved Delayed Detached Eddy Simulation method is used to analyze the leeward side vortex structure. It is found that when the angle between the vortex generators and the relative wind is 30°, the rolling moment of the train is minimized, as it significantly reduces side forces while preventing excessive growth of lift force inducing rolling moment. The reduction in rolling moment of the train by vortex generators is attributed to the suppression of leeward side trailing vortices of the train, which delays flow separation at the roof of the train, inducing a downward trend in the separated flow. Dynamic Mode Decomposition reveals that vortex generators do not alter the stability of near-body trailing vortices but enhance the pulsatile characteristics of far-body trailing vortices, which do not affect the pressure distribution on the leeward side of the train.