CFD Study of Effect of Elliptical Baffle Wind Barrier on Traffic Wind Environment of a Bridge
A detailed computational fluid dynamics(CFD)study was conducted to investigate the influence of an elliptical baffle wind barrier(EBWB)on the traffic wind environment of a bridge with a composite double-sided box section.The independence of the turbulence model,time step,and grid density was first analyzed.The crosswind reduction factors of the bridge with EBWB and a conventional rectangular baffle wind barrier(RBWB)on a 1.71 m high crash barrier were compared,and the traffic wind environments with and without RBWB were also obtained.The effects of the porosity and height of the EBWB on the traffic wind environment of the bridge were analyzed using the crosswind reduction factor,wind profile curve,and flow field structure.A comprehensive index that takes into account the static drag coefficient was introduced to determine the optimal wind barrier design.The results show that the difference between the calculated static aerodynamic coefficients of two turbulence models,SST κ-ω and RNG κ-ε,is small,with only a 4.02％difference for drag coefficient at zero wind attack angle,indicating that the current numerical simulation method is reliable.The EBWB has a satisfactory wind reduction effect,similar to that of the RBWB,and the bridge with the EBWB has a smaller cross wind reduction factor and a larger drag coefficient.The traffic wind environment of a bridge can be improved by reducing the EBWB porosity or increasing the EBWB height;however,wind loading increases proportionately.For the bridge with a composite double-sided box section in this study,an optimal EBWB design is considered to be one with 52％porosity and a 1.486 m high wind barrier(3.196 m high total barrier),taking into account the traffic wind environment and wind loading.
bridge engineeringtraffic wind environment of bridgeCFDwind barrierporositycrosswind reduction factor
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