CROSSWIND STABILITY OF A HIGH-SPEED TRAIN ON A BRIDGE

摘要

This work presents aerodynamic results of crosswind stability obtained numerically for high-speed train with 350km/h which is on top of a 14m high bridge. Variations of the incidence flow velocity from 15m/s to 25m/s with respect to the direction of the forward train motion resulted in the development of distinctively different flow patterns. To compute numerically the different flow structures, the threedimensional Reynolds-averaged Navier-Stokes equations, combined with the k-ω turbulence model, were solved on a multi-block structured grid using a finite volume technique. The pressure-velocity fields were coupled using the simple algorithm. Results of numerical investigations of high Reynolds number flows past a real train geometry under different wind velocity conditions are summarised. The body of the train includes most important details including bogies, inter-car gaps, pantograph and rotating wheels on the rail. The results of computation show that aerodynamic forces and moments augment remarkably as the wind velocity increases. The state which can cause a derailment or overturning occurred on wind velocity equaling to 25m/s and the leading car most likely to capsize. The analysis results provide the helpful reference to catch the flow field characteristics under the effect of the different crosswind velocity intensity, and the numerical simulation study of the flow field around the train under the crosswind effects can be based on these results.