Abstract:
To investigate the flow characteristics of the transient flow field around a moving train on the bridge passing through the tornado wind field, vehicle-bridge coupling aerodynamic characteristics in a harsh environment are numerically simulated to ensure operational safety. This study uses numerical simulations based on the three-dimensional incompressible N-S equations and the
k-
ε turbulence model, to analyze the surface pressure distribution and aerodynamic forces of a train on the bridge under different lateral distances between the moving train and the tornado center as well as different operational speeds passing through the wind field. The results show that: 1) The surface pressure coefficient of the train shows a decreasing trend as the lateral distance from the center of the tornado increases, and such a trend is more obvious on the leeward side compared to the windward side; 2) As the train approaches the center of the tornado along the longitudinal direction, the pressure distribution around the train presents a change from the symmetrical to asymmetrical distribution. The reverse symmetry characteristics appear after the train passes through the center of the tornado and moves away from the wind field; 3) With the change of the longitudinal distance between the train and the center of the tornado, the aerodynamic load coefficients of the head carriage show bimodal features, and the tail peak is more significant than the head peak. Moreover, as the operational speed of the train decreases, the variation of peak values of aerodynamic load coefficients with the lateral spacing from the center of tornado becomes more obvious.