Observation of Flow Downstream of a Bridge Deck Model Using Cobra Probe and Lidars

Application of lidars in civil engineering is evolving in many areas, for instance in planning and estimating design loads for long-span bridges. The use of the lidar technology in the wind tunnel provides a new option for turbulence measurements around model scale structures. The paper presents a wind tunnel test campaign using a combination of two continuous wave lidars and Cobra probes to study the flow conditions downstream of a bridge deck model, within and outside of the wake region. The measurements took place in a boundary layer flow at the wind tunnel facility of Politecnico di Milano where the performance of the two lidars for studying bridge aerodynamics was tested and is herein validated by reference Cobra probe measurements. The wake characteristics around the bridge deck are explored with the aim of improving the understanding of the nature of the wind forces acting on a bridge girder and demonstrating the potential of the remote sensing technology for wind tunnel studies relevant to bridge design.