Experimental study on the aerodynamic and wind-induced vibration characteristics of grooved stay cables

Previous studies have shown that grooves can decrease the drag of a circular cylinder (Re = 4.8 × 103–1.2 × 105), suppress vortex-induced vibration and rain-wind-induced vibration, and have potential applications in reducing the drag and damping vibrations of stay cable structures. However, the aerodynamic performance of grooved circular cylinders at high Reynolds numbers (Re = 105–106) remains unknown. Therefore, a series of wind tunnel tests were performed on grooved cables, including measurements of surface pressure, vortex-induced vibration, and dry galloping. Various aerodynamic parameters (such as surface wind pressure distribution, aerodynamic forces, and the Strouhal number), vortex-induced vibration characteristics, and dry galloping characteristics were investigated, and the results were compared with those of standard cables. The results indicated that, relative to standard cables, the average drag coefficient of grooved cables is smaller at low Reynolds numbers, and the drag reduction effect is correlated with the number of grooves, with a maximum drag reduction rate of 47%. The drag reduction effect of the grooved cables gradually decreases as the Reynolds number increases, and the grooved cables stop exerting a drag reduction effect when Re > 3.1 × 105. Compared with standard cables, the circumferential average wind pressure of grooved cables is more stable with respect to the Reynolds number, and the Reynolds number effect is weaker. The maximum amplitudes of the vortex-induced vibrations and dry galloping of the grooved cables are lower than those of standard cables. The optimal suppression efficiencies of vortex-induced vibrations for 16- and 32-grooved cables are 96.0% and 52.0%, respectively, whereas those of dry galloping for these are 75.0% and 81.8%, respectively.