Influence of the Centre Distance between Counter-Rotating Control Rods and the Circular Cylinder on FIV Suppression

Flow-induced vibration (FIV) poses significant challenges in ocean engineering, necessitating effective suppression strategies. This study presents a numerical analysis of FIV suppression using computational fluid dynamics (CFD). This article mainly studied the influence of different centre distances between control rods and main cylinder on vibration suppression within reduced velocity range of 2-14. The focus was the relationship between the transverse flow amplitude and lift coefficient of the system at reduced velocity of 10. We analysed the near-wall vorticity and pressure fields to uncover the flow-regulation mechanisms. The results reveal that control rods disrupt wake vortices and reduce negative pressure in the wake region, thereby suppressing vibrations. Compared with the bare cylinder, the vibration peak in P1 mode decreased by 35.14%. Based on the results, increasing the rod-cylinder centre distance represents a viable strategy to enhance vibration suppression performance at high reduced velocities.