One-Way Fluid-Structure Interaction of Submerged Floating Tunnel Under Current Action

The submerged floating tunnel (SFT) is a long tunnel that remains suspended below the water surface at a considerable depth of around 100–150 m and connects to land masses separated by ‘deep’ and vast water bodies. The present study aims to characterize the flow dynamics around an excessive buoyant type SFT with a circular cross-section. In this paper, one-way fluid-structure interaction analysis is carried out to analyze the dynamic behavior of SFT under current action. Computational Fluid Dynamics (CFD) is implemented to perform a 2D numerical simulation of flow around the SFT cross-section. The k-ω SST turbulence model is implemented to capture the turbulence flow around the structure. The hydrodynamic load from the CFD solver is then sequentially transferred as a uniformly distributed transient load to a structural solver to study the dynamic behavior of the SFT tube segment. In structural solver, only a part of the structure separated by mooring lines at two ends (or SFT tube segment) is considered. Here, the structure is modelled as a Euler-Bernoulli’s beam, discretized as line body elements, and supported by linear vertical springs equivalent to mooring lines at two ends. The structural response of the SFT tube segment and the flow pattern around the structure are discussed and validated from the literature.