Experiments on a yaw stay cable in turbulent flow in the critical Reynolds number

Results of an experimental campaign that focuses on the determination of the mean aerodynamic force coefficients on yawed and inclined stay cable commonly used on long-span cable-stayed bridges are presented in this paper. The tests were carried out on a long sectional model of a cable in the large boundary layer wind tunnel of Politecnico di Milano in smooth and turbulent flow. The experiments revealed that for wind speeds and turbulence level that can occur regularly on bridge sites, across-wind forces that can rapidly changes with wind speed and wind direction are present. The forces are associated with a particular aerodynamic phenomenon that occurs in the critical Reynolds number range for smooth circular cylinders and that can lead to wind-induced vibrations and cable galloping.