Numerical Study on Wall-Thickness Deformation of Flexible Risers Under Combined Internal–External Flows
Year: 2025
Type: article
Abstract: Wall-thickness deformation is a critical indicator of fatigue risk in flexible risers exposed to vortex-induced vibration (VIV), especially under combined internal and external flow conditions. This study examines the spanwise evolution and distribution of wall-thickness deformation in a riser traversing air and water. The effects of external flow velocity, internal flow velocity, and internal fluid density on in-line (IL) and cross-flow (CF) wall deformation are systematically analyzed at characteristic positions. The results show that wall deformation exhibits strong spatial variability and media property dependence: IL deformation in the air-exposed segment is amplified under lock-in conditions due to lower damping, while the submerged segment experiences consistently larger deformation driven by added-mass effects. Internal flow influences wall-thickness response in a non-monotonic manner, and increased internal fluid density suppresses deformation while shifting the dominant frequency. These findings demonstrate that wall-thickness deformation is a sensitive and integrative response to fluid–structure interaction, offering a direct basis for identifying high-risk zones and improving fatigue-resistant design in deep-sea riser systems.
Source: Fluids
Authors: Zihan Sun, Jianguo Lin, Dong Wang, Yanni Hao
Language: English
Subfield: Computational Mechanics
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,172
OpenAlex ID: W4415997874