Experimental and simulation research on the aerodynamic effect on a train with a wind barrier in different lengths

Wind tunnel tests and the improved delayed detached eddy simulation (IDDES) were carried out to study the aerodynamic characteristics of a train with a wind barrier in different lengths. The results were obtained at 20 degrees and 30 degrees yaw angles, which are the highest realistic values for high-speed trains. The rationality of the experiment was assessed according to standards, based on which the accuracy of numerical simulations was validated. After the validation, further cases that were difficult to conduct in wind tunnel experiments were simulated to explore how the barrier length affects the train aerodynamics. Results show that the length of the wind barrier has an obvious influence on the head car other than the tail car. As the length of the wind barrier increases, the lift force of the head car decreases, while the lateral force increases, and the drag force approaches to 0. The lateral and drag forces of the head car do not change significantly when the wind barrier length was longer than 66.49H at a 20 degrees yaw angle and 40.54H at a 30 degrees yaw angle.

Automated summary

The length of the wind barrier has a significant influence on the aerodynamic characteristics of the head car, with lift force decreasing, lateral force increasing, and drag force approaching 0 as the barrier length increases. The lateral and drag forces of the head car remain relatively stable after a certain barrier length at specific yaw angles.