Two-phase flow induced vibrations in a marine riser conveying a fluid with rectangular pulse train mass

• Published in: Ocean engineering Vol. 174; pp. 71 - 83
• Main Authors: Cabrera-Miranda, José Manuel, Paik, Jeom Kee
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.02.2019
• Subjects: Cumulative fatigue damage; Curved pipe conveying fluid; Steel lazy wave riser (SLWR); Time-varying mass parametric vibration; Two-phase flow-induced vibration; Ultimate limit state (ULS); Ultimate limit state (ULS); Time-varying mass parametric vibration; Steel lazy wave riser (SLWR); Two-phase flow-induced vibration; Curved pipe conveying fluid; Cumulative fatigue damage
• ISSN: 0029-8018; 1873-5258
• DOI: 10.1016/j.oceaneng.2019.01.044

A riser conveys fluids from a subsea system to a host floater; however, oil and gas phases may alternate, increasing pipe's stress and damaging downstream facilities. This paper studies the nonlinear planar vibrations of a steel lazy wave riser excited by slug flow. The employed formulations comprise the Euler-Bernoulli beam model and the steady plug-flow model with a time-space-varying mass per unit length in the form of a rectangular pulse train. The equations are solved by a Runge-Kutta finite difference scheme and frequency-response curves are constructed for effective tension, curvature, usage factor and fatigue damage. The results offer a useful insight of the slugging frequencies and slug lengths that may receive attention during the design of risers. [Display omitted] •Influence of two-phase flow induced vibration (2-FIV) on structural limit states for a marine riser.•The governing equations of motion are solved by Runge-Kutta-finite difference numerical analysis.•Large amplitude motions are observed at the bottom end of a steel lazy wave riser.•2-FIV can consume substantial percentage of the ULS usage factor, and cause serious fatigue damage.