Study on the influence of heavy train speed on the characteristics of wind flow field at tunnel entrance

Conducting research on the impact of heavy train speed on the characteristics of the wind flow field at the tunnel entrance is crucial for minimizing the waste of coal dust and coal resources resulting from the "piston wind" effect upon the train's entry into the tunnel. Liangjiashan Tunnel uplink as the object of study, based on FLUENT software to establish a dynamic grid model, simulation and analysis of heavy trains at different speeds, different locations at the wind speed and wind pressure change rules, and on-site wind speed and wind pressure real-time monitoring, the alignment between the measured outcomes and simulation findings demonstrates the high precision of the simulation process. The analysis reveals a direct correlation between variations in wind pressure and wind speed with the speed of the heavy train. Notably, the maximum piston wind pressure is observed at a distance of 20 meters from the tunnel entrance, while the maximum piston wind speed occurs at the tunnel's immediate vicinity, at 0 meters. the flow field wind pressure changes compared to the position of the train has a preemptive, the flow field wind speed changes have a lagging; when heavy trains enter the tunnel at speeds of 60 km/h or lower, the train speed can be efficiently mitigated within the tunnel entrance region, minimizing its impact on the wind flow dynamics.