Experimental investigation of vortex-induced vibration suppression in partially submerged cylindrical hulls using flow-control rods

Author(s)

Silva, Monica L. L. ; Silva, Paulo H. N. ; Assi, Gustavo R. S.

• Document type: Journal article
• Source: OCEAN ENGINEERING; v. 336, p. 9-pg., 2025-09-01.

Abstract

This study adds and focuses on the limited draft condition to the vortex-induced vibration line of scientific work. A partially submerged circular cylinder was equipped with passive flow-control rods, allowing draft variation. Tests were conducted in a recirculating water channel with a free surface, maintaining subcritical Froude numbers to minimize wave effects. A rigid acrylic cylinder, oscillating only in the cross-flow direction, was fitted with eight rigid rods evenly distributed around its perimeter. Three aspect ratios (L/D = 1.0, 1.5, and 2.0) were tested over Reynolds numbers from 10,000 to 50,000. Results show that control rods consistently reduced vibration amplitudes by over 40%, peaking at 49% for L/D = 1.5, while preserving the fundamental shedding mechanism. The synchronization range was slightly narrowed, and residual vibrations due to turbulence were observed. Mean drag and lift fluctuations also decreased significantly, with drag reductions between 26% and 38%. These results demonstrate the effectiveness of passive flow control for VIV mitigation in finite-length cylinders, offering insights for offshore platform design in the energy transition. (AU)

• FAPESP's process: 22/03698-8 - OTIC Offshore Technology Innovation Centre
• Grantee: Gustavo Roque da Silva Assi
• Support Opportunities: Research Grants - Research Centers in Engineering Program
• FAPESP's process: 11/00205-6 - Investigation of new methods for suppressing flow-induced vibrations of offshore structures
• Grantee: Gustavo Roque da Silva Assi
• Support Opportunities: Regular Research Grants