Dynamic analysis in (3 + 1) dimensions of the fluid-structure interaction of an anchored floating pontoon in oceanic waves

Abstract

The development of giant waves represents a fundamental information field in oceanic research, such as energy harvesting. In this work, we consider the effects of fluid-structure interaction (FSI) in studying and analyzing the dynamics of a floating pontoon immersed in Newtonian fluid flow. In this respect, a nonlinear coupled model, based on the Navier–Stockes and Navier–Lamé equations, is applied to solve the fluid-structure interaction problem. To this end, a set of coupled dynamical equations is established, and using the multi-scales method, a coupled complex Ginzburg–Landau equation is derived. First, it is demonstrated that Young's modulus (E) as well as the Poisson's ratio (νs) have considerable effects on the giant waves occurrence. In this regard, we have obtained a critical value of νs above which giant waves can occur, meanwhile, the results obtained also indicate that the increase in E decreases the probability of giant wave formation. Moreover, the dynamic study to explore the dynamical responses from the interaction between the fluid and the structure exhibits different phase portraits that depend on the temporal frequencies of the incident wave from the flowing fluid (ω) and the frequency of the fluid wave reflected by the structure (ω′). These results aim to find applications in the marine industry, where they can be applied to problems related to the stability of ships and offshore structures, sea-keeping problems, and resistance to wave actions. They could also be used to develop floating offshore wind turbines and dimensional buoys for energy harvesting from the ocean surface.