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Description
Accurate determination of cross-sectional aerodynamic forces - lift, drag, and pitching moment - is fundamental to evaluating the stability and wind-induced response of long-span suspension bridges.
This paper assesses the suitability of a short open-section wind tunnel facility for prediction of the aerodynamic force coefficients of the streamlined box girder of the Lysefjord Bridge. The investigation is part of a larger experimental study related to the safety of vehicles crossing the bridge. The tests were conducted on a 1:15 sectional model equipped with high-density arrays of pressure taps under three configurations: bare girder, girder with railings and girder with railings plus a static vehicle model. An array of adjustable pitching flaps was utilised to control inflow inclination. Detailed velocity profiles were measured upstream of the model using a 5-hole pressure probe to map local flow pitch angles, velocity magnitudes, and turbulence characteristics. Net sectional forces, including their mean and fluctuating components, were established by integrating the sectional surface pressure distributions.
The wind tunnel surface pressure distributions and derived force coefficients are evaluated against both model-scale and full-scale data, obtained respectively from previous wind tunnel tests conducted in a closed-section test facility and from an extensive long-term measurement campaign on the Lysefjord Bridge, conducted by the University of Stavanger. The comparative analysis highlights how local inflow adjustments in short open-section test environments translate into effective full-scale pitch angles, demonstrating the reliability and limitations of compact wind tunnel setups for full-scale load prediction.
| Topic Area | Wind Engineering and Industrial Aerodynamics |
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