TY - EJOU AU - Wang, Pengyu AU - Li, Tian AU - Zhang, Jiye AU - Zhang, Keyue AU - Zhang, Jiawei TI - Pressure Wave Numerical Simulation of Passenger–Freight Train Passing on Steel Truss Bridges T2 - Computer Modeling in Engineering \& Sciences PY - 2026 VL - 148 IS - 2 SN - 1526-1506 AB - With the continuous expansion of rail transport capacity and the increasing speeds of freight trains, it has become increasingly common for passenger and freight trains to share the tracks on double-track or high-speed rail sections. To reveal the evolution of pressure wave characteristics during non-uniform-speed encounters between high-speed trains and freight trains on bridges, this study establishes a full-scale computational model of a steel truss flexible arch bridge and the conditions under which a train passes over it, with the bridge model serving solely as an aerodynamic boundary condition. The numerical simulation is based on the three-dimensional compressible unsteady Navier-Stokes equations and the k–ε two-equation turbulence model, combined with sliding mesh technology. The computational domain includes stationary and moving regions with interface data exchange, and the mesh is generated using Poly-Hexcore with a refined boundary layer to ensure y+ values within acceptable ranges. A systematic grid sensitivity analysis is conducted, and the numerical method is validated against wind tunnel test results for stationary trains, showing good agreement. The results indicate that during the passing of a passenger train and a high-speed freight train, pressure fluctuations occur due to factors such as bogies and vehicle clearances; pressure waves on the passing side are significantly greater than those on the non-passing side, and pressure wave values gradually decrease near the roof measurement points; for freight train cars, the full-wave peak values at the mid-point measurement locations on the passing side exhibit a linear relationship with the square of the speed; for passenger trains, when the freight train’s speed exceeds 160 km/h, the full-wave peak values at the central measurement points on the passing side of each car exhibit an approximate exponential increase; during the passing of freight trains, the full-wave peak values at the measurement points on the passing side of the freight train are 49.9%–52.9% higher than those during the passing of passenger-freight trains; when passenger trains pass each other, passenger-freight full-wave peaks are 6.3%–9.9% higher than passenger-passenger peaks. These research findings provide a theoretical basis and data support for the aerodynamic safety of trains passing on mixed-traffic lines, as well as for vehicle body selection and optimized design. KW - High-speed trains; freight trains; steel truss flexible arch bridges; trains passing on the bridge; pressure wave DO - 10.32604/cmes.2026.083990