Multi-modal Vortex-Induced Vibrations of a vertical riser pipe subject to a uniform current profile

• Published in: European journal of mechanics, B, Fluids Vol. 23; no. 1; pp. 209 - 218
• Main Authors: Willden, Richard H.J., Graham, J.Michael R.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Paris Elsevier Masson SAS 2004; Elsevier
• Subjects: Added mass; Computational Fluid Dynamics; Exact sciences and technology; Fluid dynamics; Fundamental areas of phenomenology (including applications); Multi-modal vibration; Physics; Riser pipes; Rotational flow and vorticity; Separated flows; Solid mechanics; Structural and continuum mechanics; Vibration, mechanical wave, dynamic stability (aeroelasticity, vibration control...); Vibrations and mechanical waves; Vortex-Induced Vibration; Vortex-Induced Vibration; Added mass; Multi-modal vibration; Riser pipes; Computational Fluid Dynamics; Riser pipe; Vortex shedding; Computational fluid dynamics; Swirling flow; Circular cylinder; Numerical simulation; Fluid structure interaction; Oscillating cylinder
• ISSN: 0997-7546; 1873-7390
• DOI: 10.1016/j.euromechflu.2003.09.011

The transverse Vortex-Induced Vibrations of a long (length to diameter ratio, L/ D=1544), flexible pipe, that was subjected to a uniform current profile (Reynolds number, Re=2.84×10 5) have been simulated using a strip theory Computational Fluid Dynamics model. The pipe's mass ratio (the ratio of the pipe's mass to the mass of fluid displaced by it) was varied between 1.0 and 3.0 in order to study its effect upon the vibrational behaviour of the pipe. Despite the inflow current being uniform the pipe was observed to vibrate multi-modally. Furthermore, all of the excited modes vibrated at the excitation (Strouhal) frequency. The fluid, via its added mass, was found to be able to excite modes whose natural frequencies differed from the excitation frequency. This ability was observed to decrease with increasing mass ratio.