Numerical simulation of two trains intersecting in a tunnel

• This paper used a numerical model to study two trains intersecting in a tunnel.
• The wall pressure, drag and side force coefficient on the train are calculated.
• The pressure caused by two trains intersecting is larger than that of a single train.
• The influences of train speed, blockage ratio, length ratio and location are studied.

This study uses a three-dimensional, compressible, turbulence model to investigate the pressure waves generated by two trains passing each other in a tunnel. The turbulent flow around the train bodies is computed by the RNG k–ɛ turbulence model; a sliding mesh method is utilized to treat the moving boundary problem. The numerical results are verified through the results of laboratory experiment and field observation. Then, a series of numerical simulations are carried out to examine the influences of the tunnel length, the blockage ratio, the train speed and the intersecting location on the interactions of aerodynamic waves generated by the trains. The simulation results reveal that the pressure and drag coefficients of the trains reach a maximum when the two trains intersect at the mid-point of the tunnel and the values of pressure and drag coefficients increase as the train speed and the blockage ratio increase due to the train/tunnel interaction. However, the side force coefficient is dominated by the train/train interaction and its maximum value occurs when the two trains are aligned side by side.