CFD simulation of multiple moored floating structures using OpenFOAM: An open-access mooring restraints library

It is not uncommon to observe multiple floating structures in proximity in the coastal and ocean environments. Individually moored or interconnected through hinges or shared mooring lines, these structures can be constructed to form an offshore floating wind farm, a wave energy converter array, or an aquaculture farm. This paper presents the development and application of a Computational Fluid Dynamics model coupled with mooring analysis codes to simulate the dynamic response of multiple moored floating structures. Both the six degrees of freedom rigid body motion library and the multibody dynamics library in the open-source finite volume CFD toolbox, OpenFOAM, are extended with a quasi-static mooring model and two dynamic mooring models. The overset grid method is adopted to account for the mesh motions of multiple rigid bodies. The coupled CFD-mooring model is validated against experimental measurements for a single box-type floating breakwater and a twin floating breakwater moored in regular waves, as well as the steady-state postures of an underwater towed system. The coupled model is also verified by comparing OpenFOAM results with those of a Smoothed Particle Hydrodynamics solver. The mooring restraints library developed in this work, foamMooring, is open-source and can be applied to simulate the multibody systems involved in emerging offshore wind and wave energy technologies and open ocean aquaculture farms.