A Study of the FIV of a Subsear Jumper due to Multi-phase Internal Flow with an Objective of Understanding Life-cycle Fatigue

A study was conducted to anlyze the flow induced vibration due to internal multiphase flow. The approach uses the Abaqus co-simulation feature in STAR-CCM+® to fully couple the fluid dynamics of the internal VOF flow to the Jumper structural mechanics. This study focuses on the internal flow and assumes the Jumper external flow is quiescent. Several different simulations were conducted

1. The simulation of the internal VOF flow in a rigid Jumper to study the major fluid dynamics modes.
2. An eigenmode analysis to examine the modes of vibration in a quiescent internal and external fluid.
3. A two-way coupled simulation to understand the response frequency and damping in the structure due to the internal VOF  flow
4. A one-way coupled simulation where the fluid loads from a.  are used to study the FIV in the structure

The consequences of various assumptions regarding “added mass and added damping” applied in the one-way coupled solution  may then be evaluated by comparison to the fully coupled solution particularly in terms of fatigue.