Study on the effects of air blowing on operation characteristics of high-speed trains with pantograph raised and lowered

To address the aerodynamic performance challenges caused by cavity flow in the pantograph area of high-speed trains, this study investigates a three-car train set using the improved delayed detached eddy simulation method based on the SST (Shear Stress Transport) k-ω turbulence model to systematically simulate active flow control with varying blowing angles and speeds. The results indicate that blowing control disturbs the airflow beneath the pantograph, significantly altering both the magnitude and distribution of positive and negative pressures in this region, this is the primary mechanism behind the reductions in pantograph drag and tail car lift. Blowing control also optimizes the flow-field structure and effectively weakens vortex intensity. At a train speed of 350 km/h, with a blowing angle of 45° and a blowing speed equal to 0.30 times the train speed, the overall train drag reduction reaches 5.79% during pantograph lifting with the pantograph drag reduced by 28.98% and the tail car lift decreased by 11.63%. During pantograph lowering, the overall train drag reduction is 6.96%, the pantograph drag decreases by 29.56%, and the tail car lift is reduced by 13.2%.