Study of aerodynamic characteristics of a high-speed train with wings moving through a tunnel

A high-speed train with wings (HSTW) is a new type of train that enhances aerodynamic lift by adding wings, effectively reducing gravity, to reduce the wear and tear of wheels and rails. This study, based on the RNG k-epsilon turbulence model and employing a sliding grid method, investigates the aerodynamic effects of HSTWs with different angles of attack when passing through tunnels. The precision of numerical simulation method is validated by data obtained through a moving model test. The results show that the lift of the HSTW increases upon entering the tunnel, with an average lift in the tunnel of 33.3% greater than that in the open air. The angle of attack is reduced from 12.5 degrees to 7.5 degrees when the train enters the tunnel, which can better reduce the lift fluctuations and concurrently also reduce the peak-to-peak pressure on the surface of the train and the tunnel, which is conducive to the train passing through the tunnel smoothly; hence, the angle of attack for the HSTW when passing through a tunnel is adjusted 7.5 degrees. Furthermore, a comparison between the high-speed trains with and without wings demonstrates that the frontal pressure of the trains increases due to the blockage effect caused by the wings, while the rear of the trains experiences decreased pressure, which is primarily influenced by the wing wake. The outcomes of this study provide technical support for HSTWs passing smoothly through tunnels.