Session: 08-03-01 Fundamental Vortex Induced Vibrations & Cylinder Hydrodynamics

Submission Number: 180754

Effects of Marine Growth on the Hydrodynamic Coefficients of an Oscillating Cylinder in the Critical Reynolds Number Regime 

Marine cables and cables in long-term ocean service are subject to marine growth, which significantly alters their surface roughness and geometry. These changes directly influence their hydrodynamic characteristics and vortex-induced vibration (VIV) responses under ocean currents. However, existing experimental studies on the effects of marine growth have primarily focused on low Reynolds number (Re ~ 10⁴) conditions, the effects at higher and more operationally relevant Reynolds numbers (Re ~ 10⁵) remains limited. This study investigates the influence of marine growth in the critical Reynolds number region through forced oscillation tests on a 10-inch rigid cylinder with hard marine growth coverage. Real shellfish were attached to the cylinder surface to reproduce the roughness and irregular morphology associated with marine growth. The excitation, drag, and inertia forces were systematically measured over a range of oscillation amplitudes and frequencies to establish a hydrodynamic coefficient database for fouled cylinder in the critical Reynolds number region . The results show that marine growth significantly alters the hydrodynamic characteristics of the fouled cylinder. Compared to a smooth cylinder, its drag coefficient is amplified, the distribution and magnitude of the excitation coefficient are shifted, and the added mass coefficient is also significantly increased. Furthermore, the hydrodynamic behavior of the fouled cylinder at high Reynolds numbers shows pronounced deviations from trends observed in previous low-Re experiments.

Presenting Author: Ruoning Du State Key Laboratory of Ocean Engineering, Shanghai Jiao Tong University

Presenting Author Biography: I am Du Ruoning, a doctoral student from Shanghai Jiao Tong University. My research field is oceanic pipe cable vortex-induced vibration.

Authors:

Lusheng Jia CNOOC Research Institute Co., Ltd
Yi Liu CNOOC Research Institute Co., Ltd.
Dejun Wang CNOOC Research Institute Co., Ltd.
Ruoning Du State Key Laboratory of Ocean Engineering, Shanghai Jiao Tong University
Jiawei Shen State Key Laboratory of Ocean Engineering, Shanghai Jiao Tong University
Mengmeng Zhang State Key Laboratory of Ocean Engineering, Shanghai Jiao Tong University
Leijian Song State Key Laboratory of Ocean Engineering, Shanghai Jiao Tong University