Numerical simulation of aerodynamic characteristics of wind-vehicle-bridge system

The computational fluid dynamics (CFD)-based numerical simulation was used to investigate the aerodynamic performance of the CRH2 (China railways high-speed train) and bridge under strong winds. Specifically, the aerodynamic characteristics of the vehicle-bridge-wind systems with/without wind barriers were comprehensively discussed. Aerodynamic drag force, lift force, overturning moment together with the surface pressure of the train were studied. In general, the drag force and overturning moment coefficients of the head car presented the maximum values, while the minimum ones were associated to the tailing car. The wind barrier could improve the surface pressure distributions of the high-speed moving vehicle on the viaduct, and hence the overall aerodynamic performance. For example, the mean aerodynamic force coefficient of the train was also reduced since the air compression around the train was more uniform. In addition the pulse fluctuation and amplitude of the aerodynamic force coefficient of the bridge with a high-speed running train were also improved due to the wind barriers.