翻译：3 高速列车底部流场特性图6为不同吹气速度下头车的阻力对比在吹气速度为4 ms时方案1的头车阻力降低了1955方案1的头车阻力降低了1006。在吹气速度增加的情况下压差阻力比粘性阻力下降得更为明显可见吹气主要改变了列车的压差阻力。图7为转向架1区域和转向架2区域在平面1上的压力分布转向架前部的区域在吹气的作用下压力增加当其作用在转向架舱前端墙时会产生一个与阻力相反的力从而减小了列车的压差阻力

Flow field characteristics at the bottom of the high-speed train Figure 6 shows a comparison of the drag of the leading car under different blowing speeds. When the blowing speed is 4 m/s, the drag of the leading car in scheme 1 decreases by 19.55%, and the drag of the leading car in scheme 2 decreases by 10.06%. As the blowing speed increases, the pressure difference drag decreases more significantly compared to the viscous drag, indicating that blowing primarily changes the pressure difference drag of the train. Figure 7 shows the pressure distribution on plane 1 in the area of bogies 1 and 2. The blowing increases the pressure in the front area of the bogies, which generates a force opposite to the drag when acting on the front wall of the bogie compartment, thereby reducing the pressure difference drag of the train. In addition, scheme 1 has a larger blowing area, which leads to a larger area of pressure increase that is closer to the front wall of the bogie compartment, resulting in a more significant drag reduction effect. Figure 8 shows the streamline distributions on plane 1 within each bogie area under two blowing schemes: the original model and blowing speed of 4 m/s. It can be seen that blowing from the top of the bogie compartment changes the flow field structure of the bogie area: (1) In the original model, the airflow rotates with the wheelset, and some of it detaches at the rear of the wheelset and rises to enter the inside of the bogie through the airflow that detaches at the front wheel, while the airflow detaching at the rear wheel moves forward along the bogie compartment wall from back to front, and both airflows converge at the frame crossbeam. (2) Taking bogie 2 as an example, in scheme 1, the airflow can only rise to the surface of the brake disc and is then released by the blowing mouth to descend, unable to reach higher areas, while the airflow in scheme 2 can reach higher positions, forming a vortex in the blowing area before leaving the bogie area, instead of flowing forward as in the original model. In bogie 3, due to the structural differences between the bogies of the motor car and trailer, there is no influence of the brake disc on plane 1, and the airflow in both schemes shows a downward trend with little upward flow. (3) In both blowing schemes, the collision of the upward and downward airflows results in lower flow velocities in the bogie area compared to the original model. Figure 9 shows a comparison of the frictional wind speeds on the surface of bogie 2 between the original model and the two schemes (blowing speed of 4 m/s). Blowing changes the flow field characteristics of the bogie area, and thus the frictional wind speeds on the surface of the bogie also change. Table 6-2 shows the average increase in frictional wind speed on the surface of bogie 2 components under blowing, indicating that the frictional wind speed in scheme 1 is higher than that in scheme 2, and the frictional wind speeds on various dampers are higher than those in the original model, meaning that snow particles on these components will bear greater shear forces and cause unstable sedimentation.