Experimental Verification of Flow-Induced Vibration Fatigue of a Flexible Tube Array With and Without Strakes Available to Purchase

The flow-induced vibration fatigue of an array of tubes is a complex problem of practical significance in the offshore oil and gas industry. Simple analytical tools for analyzing isolated tubes lack the capability of directly addressing the array problem, so they require some sort of calibration if they are to be used for this application. Computational fluid dynamics (CFD) and coupled computational fluid-structure interaction programs can also be utilized to address the problem in more detail, but at a significant cost in computing time. In either case, understanding of the phenomena is limited, and relatively little relevant data are available to verify the accuracy of these programs for this application. This paper documents a physical model test performed at the University of California-Berkeley Richmond Field Station Tow Basin with the following objectives: to improve confidence in the understanding of the dynamic performance and fatigue demand on both bare and straked tubes in an arrayed configuration; to estimate the influence of an external super-structure (e.g., the truss section of a floating truss spar platform) on the vibrations of the tubes in the array; and, to generate data for verification or calibration of state-of-the-art or emerging analysis tools. The findings provide new, useful information on both the fatigue of tubes in complex configurations and the effectiveness of suppression devices in these scenarios for fatigue mitigation.