Numerical and experimental analysis of hydroelastic response on a very large floating structure edged with a pair of submerged horizontal plates

This paper aims to investigate the hydroelastic response of the very large floating structure (VLFS) with the perforated, non-perforated or the dual submerged horizontal plates both numerically and experimentally. A modal expansion approach is applied to the fluid-structure interaction problem in the frequency domain. The boundary element method solutions based on Kelvin sources are used for the hydrodynamic diffraction and radiation forces, in which the viscous effect of the perforated anti-motion plate is taken into consideration through the Darcy's law. As a comparison of the data between calculations and experiments, the relationship between the porosity and the porous parameter is developed using the least-squares fitting scheme. The effectiveness of the attached non-perforated and perforated plates in reducing the motion of the VLFS is systematically assessed for various wave and anti-motion plate parameters, such as plate width, porosity and submergence depth. After simulation and verification, we propose a simple anti-motion device, which is the perforated-impermeable-plate combination attached to the fore-end and back-end of the VLFS. The performance of this anti-motion device has been confirmed as an optimal design. Considering variation of the water depths in offshore, discussion on the hydroelastic response of the VLFS with these anti-motion devices at different water depths is highlighted.