Aerodynamic interference between road vehicle and train during meeting on a single-level rail-cum-road bridge under crosswind

Abstract

A single-level rail-cum-road bridge is a relatively new type of bridge structure that accommodates both roadway and railway traffic on the same level. The aerodynamic interactions between road vehicles, trains, and the bridge deck under strong crosswind are significant, potentially posing safety risks to both vehicles and trains. This study aims to elucidate the aerodynamic interference between a road vehicle and a train during meeting on a single-level rail-cum-road bridge under crosswind. To achieve this, a three-dimensional, incompressible, unsteady Reynolds averaged Navier–Stokes method is utilized to simulate the meeting process between a van and a train on a prototype single-level rail-cum-road bridge under crosswind. Using an established computational fluid dynamics numerical model, the flow structure and aerodynamic loads of the van–train–bridge system under crosswind are studied. The results show that the auxiliary facilities on the bridge deck (such as pedestrian guardrails and anti-glare barriers) significantly alter the flow field around the van and train, affecting their aerodynamic characteristics. Additionally, the aerodynamic interference between the van and the train during their meeting under crosswind is substantial. The aerodynamic coefficients of the van and train, in terms of both magnitude and fluctuation, increase significantly with their driving speeds during the meeting process under crosswind. Furthermore, this aerodynamic interference intensifies as the lateral distance between the van and the train decreases during the meeting under crosswind.