Modeling the Effect of Flow-Induced Vibration on Submerged Structure

Abstract

Flow-induced vibration (FIV) poses a critical risk of fatigue and failure to submerged structures like pipelines and marine energy devices; however, predictive modeling remains challenging due to a gap in integrated approaches that combine high-fidelity simulation with experimental validation across a broad parametric space. This study therefore aimed to quantify the effects of key geometric and hydrodynamic parameters on FIV response and to develop a validated predictive framework. A combined experimental-numerical methodology was employed, testing circular, square, and D-section models in a flume under systematically varied flow velocities and turbulence intensities. Data on structural displacement and hydrodynamic forces were collected using laser vibrometry, load cells, and PIV, alongside complementary fluid-structure interaction (FSI) simulations. A stratified sampling strategy generated 600 experimental runs and 120 simulations, with data analyzed via ANOVA, regression, and uncertainty quantification. Results demonstrated that cross-sectional geometry dominated the structural response. The square section exhibited the highest mean normalized RMS displacement (0.199 ± 0.061), significantly larger (p < 0.001) than the circular (0.118 ± 0.052) and D-sections (0.095 ± 0.038). A highly significant interaction (p < 2e-16) between reduced velocity and damping ratio governed the circular section's amplitude. Furthermore, increasing turbulence intensity from 5% to 15% significantly reduced the RMS lift coefficient (p = 5.89e-7). The research provides a robust, validated model that explicitly links flow conditions to structural response, offering engineers a critical tool for designing resilient submerged infrastructure against FIV.