Safety of high-speed train passing by windbreak breach with different sizes

The safety of a high-speed train running at a speed of 120 km/h is investigated when the train passes by windbreak breach with variety of lengths subjected to normal wind speed of 32 m/s. Eight lengths of breach are investigated; 50, 35, 25, 15, 12, 10, 7 and 2m. The transient aerodynamic loads of the high-speed train are calculated using the Unsteady Reynolds-averaged Navier-Stokes (URANS) model. The simulation results are validated using field test data on the breach of 12 m length. The results showed that although the short windbreak breach produces the highest wind speed it gives the lowest wind loads compared to the longer breach. The train derails when passing by the breaches with lengths 50 and 35 m. When the breach length is between 12 m and 35 m, the first wheelset on the windward side tends to climb up the rail. When the breach length is less than 10 m, the derailment coefficient is below 0.8. The first wheelset is the most vulnerable wheelset among the four wheelsets as the train passes by the breaches. It has also been found that only when the wheel raise on the derailment side is higher than flange height the wheelset derails out of the rail.