风洞试验中不同厚度挡风墙合理长度的数值研究

In a wind tunnel, the characteristics of wind barrier have a significant effect on the aerodynamic characteristics of a train. Using the improved delayed detached eddy simulation (IDDES) method and the shear stress transport (SST) k-ω turbulence model, the variations of the aerodynamic characteristics of the train with the length of the wind barrier were studied for different wind barrier thicknesses. The wind tunnel test results were used for comparison at a yaw angle of 30°. When the wind barrier exceeded a certain length, the aerodynamic load of the train did not change significantly, and it can be considered to have reached a critical length. The critical length of the wind barrier was determined by fitting the relationship between the aerodynamic coefficient of the train and the length of the wind barrier. The relationship between the thickness of the wind barrier and the critical length satisfied the quadratic function y= − 51.235x ²+8.659x+29.014. When the thickness of the wind barrier was more than 0.5 m (full-size), the critical length could be obtained by substituting the thickness of the wind barrier into the above function during a wind tunnel test to study the aerodynamic characteristics of the train.