Slipstream at the tunnel exit induced by a high-speed maglev train passing through a tunnel

When the high-speed maglev train enters a tunnel, a compression wave generated by it will induce the air flow at the exit of the tunnel to form an adjoint velocity. The three-dimensional, compressible, unsteady calculation method is used to simulate the process of the high-speed maglev train passing through a tunnel with different blocking ratios under different speeds. The features of the slipstream around the tunnel exit induced by the compression wave are analyzed, and the influence of the train speed and blocking ratio on the slipstream is ascertained. The results show that at the tunnel exit, the trend and the peak speeds of the slipstream induced by the compression wave have no apparent change in the direction of the train’s movement; the peak wind speed of the measuring point outside the tunnel exit gradually decreases in the longitudinal range of 25 m, and basically remains unchanged in the transverse range of 5 m. With the vehicle speed and blocking ratio increasing, the peak wind speeds inside and outside the outlet are raised obviously. When the train speed is 600 km/h and the blocking ratio is 17.04%, the maximum wind speed at 5 m outside the tunnel is up to 56 m/s. This conclusion is helpful to strengthen people's understanding about the harm of the slipstream induced by a train passing through a tunnel, and to provide references for protection against the slipstream in the railway tunnel and the safe operation of maglev train in the future.