Time-Dependent Simulations for the Directional Stability of High Speed Trains Under the Influence of Cross Winds or Cruising Inside Tunnels
Paper i proceeding, 2005
Large eddy simulation (LES) technique is used to study safety and comfort issues of cross-wind stability and lateral vehicle vibrations in double-track tunnels. A simplified train model is used to study flows at yaw angles of 90 and 35 degrees of the cross wind and Reynolds numbers of 300 000 and 370 000, respectively. LES results are compared with the experimental data and good agreement was found. For the LES investigation of lateral vibrations in tunnel, two high-speed trains are used, the German ICE2 and the Japanese Shinkansen S300. It is found that the lateral oscillations of the Shinkansen train originate from the shape of the rear end. Besides, the small vortices formed at the front of the train, on the center side of the tunnel, are found to govern the separation at the rear of the Shinkansen train. The frequency of the lateral oscillations of the Shinkansen train in LES is St=0.09 compared to St=0.1 measured at full scale tests. In the same time no dominant frequency is found on the ICE2 train.