Jian Tan , Yu Zhang , Yulong Zhang , Le Sun , Shuai Cui , Chen An , Segen F. Estefen
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引用次数: 0
Abstract
Vortex-induced vibration (VIV) poses significant challenges to the structural reliability of Cold-water pipes (CWPs) in Ocean Thermal Energy Conversion (OTEC) systems, particularly when geometric variation and non-uniform axial tension are present. This study develops a high-fidelity semi-analytical framework that combines the Generalized Integral Transform Technique (GITT) with Sturm-Liouville Eigenvalues Using Theta matrices (SLEUTH) method. To analyze the VIV of CWPs with variable cross-sections under three realistic flow profiles: uniform, linear shear, and exponential shear. Validation against finite element simulations and existing literatures confirms the accuracy of the proposed model. Results demonstrate that while uniform flow produces stable standing-wave responses, linear and exponential shear flows introduce progressive mode transitions, nonlinear mode coupling, and broadened excitation spectra. Notably, exponential shear induces spatially asynchronous vortex shedding and chaotic lock-in behavior, revealing energy transfer from dominant to higher-order modes. These phenomena are strongly influenced by the interplay between velocity gradients and structural heterogeneity. The findings provide critical insights into the physical mechanisms governing VIV and offer design guidance for mitigating fatigue-critical responses in CWPs. This work addresses gaps in the current literature by accounting for coupled geometric-tension-flow effects and proposes a robust computational tool for future engineering optimization of marine energy systems.
期刊介绍:
Ocean Engineering provides a medium for the publication of original research and development work in the field of ocean engineering. Ocean Engineering seeks papers in the following topics.