Numerical study on reasonable lengths of wind barriers with different thicknesses in wind tunnel tests

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-omega 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 degrees. 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.

Automated summary

In this study, the impact of wind barrier length on the aerodynamic characteristics of a train was investigated using the improved IDDES method and SST k-omega turbulence model in a wind tunnel. By comparing wind tunnel test results for different wind barrier thicknesses, it was found that when the wind barrier length exceeded a certain value, the aerodynamic load of the train did not change significantly, indicating a critical length had been reached. The relationship between the wind barrier thickness and the critical length followed a quadratic function y= - 51.235x(2)+8.659x+29.014. For wind barrier thicknesses greater than 0.5 m (full-size), the critical length could be determined by substituting the wind barrier thickness into the above function during wind tunnel tests to study the aerodynamic characteristics of the train.