CFD simulations of a suspension bridge deck for different deck shapes with railings and vortex mitigating devices

Aerodynamic response of a single-box suspension bridge girder is investigated using CFD simulations. The importance of including railings and vortex mitigating devices such as guide vanes and a spoiler in the simulations is explored since they alter the flow field around the deck greatly. The paper compares results from a bare deck section and a section with mitigating devices. A clear vortex shedding observed for the bare deck section is suppressed by the use of mitigating devices and the aerodynamic force coefficients are very different between these cases. The effect of varying deck width is also studied. Flutter derivatives are defined based on quasi-steady formulation and flutter velocity is computed for each section. The section with the largest width to depth ratio has the best performance against flutter. This study is an initial phase of multi-fidelity optimization of bridge deck shape considering aerodynamic constraints.