Session: 06-15-01 Unsteady Hydrodynamics, Vibrations, Acoustics and Propulsion - I

Submission Number: 178242

Influence of Flow Turbulence on Vortex-Induced Vibrations of a Circular Cylinder 

Free-stream turbulence (FST) is common in the ocean environment and can strongly affect the loads and fatigue of subsea pipelines and risers, yet many classic vortex-induced vibration (VIV) studies of bluff bodies use laminar or low-turbulence conditions. This gap limits how well laboratory findings translate to real service conditions. This study experimentally examines how turbulence intensity (TI) and integral length scale (L_s/D) affect key response features of a circular cylinder under pure crossflow or pure inline vibration. The goal is to provide a clearer link between inflow turbulence properties and VIV behavior, to better inform models and design practice under realistic ocean conditions. We perform controlled flume experiments on a circular cylinder with isolated crossflow and inline motions, with varied TI and  L_s/D via upstream grids. The preliminary results show that reduced velocity remains the primary organizer of VIV, while inflow turbulence shifts its key features. With higher TI and L_s/D, crossflow VIV shows a delayed onset of lock-in, narrower bandwidth, and slightly lower peak amplitudes, whereas inline shows the opposite: an earlier onset, wider lock-in with marginally higher peaks.  In inline motion, higher TI also sustains post–lock-in residuals consistent with turbulence-forced buffeting. These compact trends link TI and L_s/D to design-relevant metrics for more realistic VIV assessment.

Presenting Author: Zhimeng Zhang Tianjin University

Presenting Author Biography: Dr. Zhang received his Ph.D in ocean and coastal engineering in March 2023 from Tianjin University, China. He has worked as a Research Associate at Tianjin University since then and is currently a research fellow at the University of Western Australia. He works in the area of computational and experimental fluid dynamics, fluid-structure-soil interaction, and vortex-induced vibration of pipelines/cables.

Authors:

Zhimeng Zhang Tianjin University
Xianghe Li Tianjin University
Hongwei An The University of Western Australia
Scott Draper The University of Western Australia
Phillip Watson The University of Western Australia
Maryam Abdolahpour The University of Western Australia
Chunning Ji Tianjin University