A turbulent crosswind simulation method at high-speed railway tunnel entrance: Based on field test and geometric turbulence generator

It is common for high-speed trains (HSTs) to abruptly switch between a tunnel and a flat ground along high-speed rail lines. When encountering strong crosswinds, the safety of HSTs in such running scenarios will be severely threatened. The simulation of the turbulent component of an incoming crosswind is very important to restore the real aerodynamic environment of HSTs in tunnel-flat ground-tunnel (TFT) running scenario. The purpose of the present study is to determine which of the two geometric turbulence generators, the spire and the fence, is more suitable for computational fluid dynamics (CFD) simulation of a fluctuating crosswind field in the TFT scene. First, the wind field characteristics in the TFT scene are analyzed based on the field test. Then, the tunnel-flat ground-spire/fence CFD model was established based on the "mosaic"mesh technology. Finally, the difference of wind field fluctuating characteristics under two turbulence generator conditions based on improved delayed detached eddy simulation (IDDES) is discussed. The main results show that the average wind speed of the windward and leeward lines in the fence case are 60% and 43.75% higher than the corresponding values in the spire case, respectively. The main conclusions show that the turbulent crosswind generated by the spire is more consistent with the spectrum characteristics of the natural wind field.