Experimental investigation and one-way coupled fluid-structure interaction analysis of gas-liquid two-phase flow conveyed by a subsea rigid M-shaped jumper

The subsea rigid M-shaped jumpers provide reliable and flexible connections in subsea production systems by using deflection to reduce the impact of internal flow and providing installation tolerances. During their service, the gas-liquid mixed multiphase flow conveyed by the jumpers will cause flow-induced vibration (FIV) and reduce their fatigue life. In this paper, the air-water mixed multiphase flow conveyed by a rigid M-shaped jumper at different mixture velocities (1 m/s to 4 m/s) and volume fraction of water (0.2-0.8) is investigated to analyze the factors affecting the flow patterns and identify the most dangerous regions. Flow patterns in each segment and historical pressure changes are obtained by simulation and experiment. The dynamic response of the jumper excited by FIV is obtained by one-way coupled fluid-structure interaction (FSI). The evolution of the air-water two-phase flow pattern from inlet to outlet is visualized and analyzed. In particular, the regularity of Taylor bubble generation in the first ascending segment is discussed. The pressure tends to decrease from inlet to outlet, and a consistent change in pressure difference is observed between simulation and experiment. The elbows are the most notable segments, with the maximum deformation and stress concentration.