Wake-induced interactive vibrations of two tandem cables with a center-to-center distance of 2D

Abstract

The wind-induced vibrations of a pair of flexible cable models in tandem arrangement were experimentally studied. The center-to-center distance of two flexible models was fixed at 2D. Both models were free to vibrate in both in-plane and out-of-plane directions. The wind speed varied from 3 to 35 m/s, corresponding to Reynolds numbers in the range of 0.96 × 104–1.12 × 105. The response characteristics, including the vibration amplitude, non-dimensional trajectory, and dominant frequency, were analyzed. For the first time, strong vibration of the upstream model caused by the interactive effects between the upstream and downstream models was observed in the wind tunnel tests. The vibration pattern of the two models changed twice in the entire wind speed range. Accordingly, two critical wind speeds were determined—the first is the onset wind speed of the in-plane vibration of the downstream model; and the second is the onset wind speed of the out-of-plane vibration of downstream model and the vibration of the upstream model. According to the vibration response characteristics and interactive patterns, the wake-induced vibrations of the two models were divided into three stages—weak interaction, stronger interaction, and strong interaction. Finally, the reasons for the different vibration patterns were examined and qualitatively evaluated.