Aerodynamic Response and Running Posture Analysis When the Train Passes a Crosswind Region on a Bridge

Abstract

Trains running on a bridge face more significant safety risks. Based on the Unsteady Reynolds-Averaged Navier–Stokes turbulence model, a three-dimensional Computational Fluid Dynamics computational model of the train–bridge–wind barrier was proposed in this study to measure the transient aerodynamic load of the train. The transient aerodynamic load was input into the wind–train–bridge coupling dynamic system to perform dynamic analysis of running safety. Significant fluctuations in the aerodynamic coefficients were found when the train entered and exited the wind barrier due to the dramatic change in flow pattern. The maximum value of the derailment coefficient decreased with the height of wind barriers, which hardly affected the wheel load reduction rate. The 2 m high wind barrier had no evident influence on the running posture of a general high-speed train, while the 4 m high wind barrier was proven to have better protection. Over-protection was found with an even higher wind barrier.

Capability analysis of computational fluid dynamics models in wind shield study on Queensferry Crossing, Scotland

“…The derailment coefficient decreased with the increasing height of wind barriers, up to a limit of about 4m. The findings from Zhang et al (2020) and Yan et al, (2021) confirm the findings of Procino et al (2008) who suggested that the wind velocity would decrease as wind shields porosity decrease and barrier wall height increased. While the work discussed above represents significant advancement in the numerical analysis of dynamic wind-bridge interaction for wind shields, it is largely theoretical.…”

“…By their nature, bridges tend to be constructed in areas that are exposed to strong wind conditions, such as canyons, lakes and rivers (Bastos et al, 2018;Lin et al, 2018). As a result, there can be concerns over vehicle safety, and often speed limits on vehicles are implemented (Yan et al, 2021). Installing wind shields on bridges can effectively protect vehicles as they create low-wind zones, reducing the risk of strong winds (Kozmar, H., Procino, L., Borsani, A. and Bartoli, 2012;Ma, C., Duan, Q., Li, Q., Liao, H. and Tao, 2019).…”

“…The perforated wall can also effectively reduce the wind velocity and result in relatively smaller eddy-related issues than non-perforated walls with the same height. (Yan et al, 2021) developed a 3D CFD model of a train-bridge-wind shield to measure the transient aerodynamic load of the train. Significant fluctuations in the aerodynamic coefficients were found when the train entered and exited the wind shield due to the dramatic change in flow pattern.…”

Influence of Posture Change on Train Running Safety under Crosswind

“…Based on previous research, different running posture changes were found when the leading car, the middle car, and the trailing car passed through the crosswind area [26].…”

“…Furthermore, the coupled dynamic system provides the posture changes of the train passing through the crosswind region with and without the given posture. The running posture is a part of the safety analysis and was studied by a previous study [26], while only the posture of the leading vehicle was investigated. In the present study, the posture changes of the leading, middle, and trailing cars of the trains with and without the initial posture in five degrees of freedom (lateral and vertical displacement and rotation in three directions) were compared and analyzed.…”