Numerical analysis of floating structures using a fluid-structure interaction model for free surface flows and anchored bodies

Resumo

The present work is dedicated to the numerical simulation of Fluid-Structure Interaction (FSI)
problems involving floating bodies subjected to the action of free-surface flows, where the structure may or may
not be anchored through mooring cables. The numerical model proposed here may be utilized in several practical
applications, such as: ships hydro-aerodynamics, stability of oil extraction platforms, efficiency of wave energy
converters, stability of floating bridges, floating houses and buildings. In the present model, the fluid equations
are discretized using the Characteristic-Based Split (CBS) method in the context of the Finite Element Method
(FEM). For the treatment of multiphase free-surface flows, the Level Set Method is used, where the fluid is
considered as a biphasic medium. The structure is kinematically described using a rigid body approach and the
mooring cable is modeled using an elastic material with geometric nonlinearity and the Nodal Position Finite
Element Method (NPFEM). The system of equations of motion is discretized in time using the implicit
Newmark and α-Generalized methods. Problems involving floating bodies with and without anchoring are
simulated to demonstrate the applicability and accuracy of the proposed numerical model.