Experimental investigation of distributed cross-plates effects on suppressing vortex-induced vibration of a flexible cylinder

Abstract

Distributed plates have been proven effective in controlling the vortex shedding and reducing the drag force of a circular cylinder, but more studies on its effect on vortex-induced vibration (VIV) are needed. This paper presents a systematic study of the effect of distributed cross-plates on the suppression of the VIV of a flexible cylinder using wind tunnel experiments. The experiments are performed by changing the length (l), width (w), and number (N) of the cross-plates, the spacing (S) between the adjacent cross-plates, and the aspect ratio (λ) of the flexible cylinder. The flexible cylinder is allowed to vibrate in the transverse direction for a reduced velocity range of 3.0–9.5, corresponding to a Reynolds number of 10,000–49,000. The results show that the optimal configuration of the distributed cross-plates for suppressing VIV is (l/D, w/D, S/D) = (2.0, 0.5, 4), where D is the cylinder diameter. The maximum amplitude decreases monotonically with increasing length and width, respectively. The optimal spacing is independent of λ of the flexible cylinder. For the optimal configuration, the vibration can be fully suppressed in many cases, and the minimum reduction of the maximum amplitude is 14% depending on N and λ, demonstrating a potential application of the distributed cross-plates.