Numerical simulation of vortex-induced vibration response of flexible riser with internal flow under shear flow

Vortex-induced vibration (VIV) of marine risers, instigated by ocean waves and currents, may significantly reduce the service life of risers in the exploitation of maritime petroleum resources. Consequently, investigating the VIV response of risers in complex wave-current environments is of significant technical value. The flexible risers' VIV response with internal flow under shear flow conditions is the main topic of this research. The external and internal flow fields are updated using dynamic mesh technology and a two-way fluid-structure interaction (FSI) approach in StarCCM+, which is founded on the three-dimensional N-S equations. A computational model of the VIV of flexible risers under the combined impact of internal and shear flows is created, and the model is validated through experimental comparison. On this basis, a thorough examination of the risers' VIV response to internal and shear flows is carried out. The impact of various internal and shear flow conditions, as well as the interaction between the two phases, on the vibration characteristics and mode of the riser are disclosed. The study results provide a viable technical foundation for examining the maritime flexible risers’ VIV response subjected to internal and shear flow effects.