Aerodynamic performance of traveling road vehicles on a single-level rail-cum-road bridge under crosswind and aerodynamic impact of traveling trains

Abstract

Crosswind and train-induced wind are major factors influencing the aerodynamic performance of vehicles on single-level rail-cum-road bridges. Based on computational fluid dynamics (CFD) technology, this work developed a numerical model to discuss relevant issues. The flow features of the vehicle-bridge system, the influence of different lanes and vehicles are explored, and the superposition of crosswind and train-induced wind has been analyzed. The results indicate that the crosswind and train-induced wind superpose near the windward side of the concrete wall, producing two high-pressure and low-pressure zones, which are the primary cause of the aerodynamic variations on nearby vehicles. The crosswind decreases the variation amplitude of side force, rolling moment and yawing moment for 10% ∼ 20%, but the influence on the lift force and pitching moment is not significant. Therefore, the aerodynamic forces of the vehicle while meeting the train at different wind speeds can be obtained by superposing the aerodynamic variation caused by the moving train and the aerodynamic forces at its sole-traveling state, which are conservative and can provide references for actual engineering.

Keywords

• rail-cum-road bridge
• single-level arrangement
• aerodynamic performance
• train-induced wind
• crosswind
• road vehicles