Session: 04-04-04: Rigid Pipelines IV

Submission Number: 157116

Investigation of Vortex-Induced Vibrations in Realistic Boundary Conditions 

Vortex-induced vibrations (VIV) occur when fluid flows around cylindrical structures, such as subsea pipelines and cables, cause vortex shedding that is able to generate oscillations both perpendicular and inline with the flow direction. VIV can induce fatigue damage which, in severe cases, can result in structural failure. Despite extensive research, gaps in our understanding of the drivers for such phenomena remain – in part due to limitations in experimental facilities. Many apparatus lack the flexibility to replicate the varied, real-world conditions that affect subsea pipelines/cables, such as seabed proximity and flow conditions.

As part of the TIDE Research Hub (https://tide.edu.au/) a versatile new experimental apparatus has been developed to capture the complexity of VIV across diverse configurations. The apparatus is purpose built to fit within the Large O-Tube facility located within the Coastal and Offshore Research Laboratory (CORL) at the University of Western Australia, which is recirculating flume capable of simulating current and/or oscillatory flow conditions above a mobile seabed. The unique aspects of the O-Tube include its ability to simulate a wide range of flow conditions and its sufficient size to conduct tests at nearly a 1:1 scale. Using the VIV apparatus within the O-Tube enables systematic investigation of VIV of pipelines/cables with varied diameter, surface roughness, and proximity to the bed. It can simulate real-world conditions such as turbulent incident flow, mobile seabed and it may be used (by altering the pipe) to investigate the influence of marine growth, and assess different strake designs used for VIV mitigation. Additionally, the apparatus allows for precise measurement of both one-degree-of-freedom (1DOF; i.e., either inline or crossflow) and two-degree-of-freedom (2DOF) VIV response, using integrated accelerometers and load cells that capture dynamic loads and motion characteristics under realistic mass ratios but without being intrusive. Studies considering flow directionality, unidirectional flows and wave conditions can be performed, allowing comprehensive analysis across varied hydrodynamic environments. Use of adjustable spring stiffness further allows the simulation of pipes and cables with different designs and flexibilities, supporting research across multiple structural configurations.

This paper introduces the apparatus and discusses its calibration and validation via an initial suite of experiments, demonstrating its capacity to replicate VIV behaviour accurately. The influence of 1DOF vs. 2DOF on VIV response is explored. By addressing known gaps in current experimental capabilities, the new apparatus aims to advance VIV research, supporting the offshore industry’s need for refined predictive models and more effective mitigation strategies to enhance the resilience of subsea infrastructure.

Presenting Author: Maryam Abdolahpour The University of Western Australia

Presenting Author Biography: I am a Research Fellow at the University of Western Australia (UWA), following previous research and teaching positions at UWA and the University of Melbourne. My expertise spans hydrodynamics, coastal and offshore engineering, with a focus on fluid-roughness interactions, Vortex-Induced Vibration (VIV), scour-induced instability of subsea structures, and coastal processes. My research also explores nature-based solutions for scour and erosion protection in coastal and offshore environments. In January 2022, I joined TIDE (ARC Industrial Transformation Research Hub for Transforming Energy Infrastructure through Digital Engineering), where I primarily focused on offshore pipeline design, including the development of a versatile VIV apparatus which will be the focus of one of our papers at OMAE2025.