Aerodynamic drag reduction research of air blowing in streamlined area of the head car of high-speed train

In order to explore the feasibility of drag reduction by air blowing in the streamlined area of the head car, the improved delayed detached-eddy simulation method was used to simulate the complex flow around the train at different blowing speeds. The accuracy of numerical simulation was verified by the wind tunnel test. The results show that the flow characteristics around the train can be significantly changed by blowing in the streamlined area of the head car. The airflow generated by the blowing port can avoid the direct impact of the high-speed incoming flow on the train surface. This effectively reduces the pressure drag and friction drag of the head car. Air blowing has relatively small impact on the aerodynamic drag of the middle and tail cars. Air blowing can cause interference effects on the flow around the train, increasing the turbulent kinetic energy in some areas of the train surface. When the blowing velocity increases, the drag reduction ratio and the normalized net power saving of the three-car model increase. When the blowing velocity is 0.2 times of the incoming flow, the drag reduction ratio of the three-car model is 8.44%, and the normalized net power saving is 6.74%. © 2024 Central South University of Technology. All rights reserved.