Dynamics of a Floating Solar Array Subjected to Wave and Wind Loads Using Coupled CFD-Multi Body Dynamics Simulations

_ Floating Photovoltaics (FPV) are an emerging technology which has received increasing interest in recent years. In the present study, we introduce a novel approach to model floating solar farms under various wave and wind conditions in the framework of computational fluid dynamics (CFD). A cut-cell based autonomous meshing approach is used which allows complex moving geometries to be represented easily while maintaining high-quality Cartesian cells throughout the simulation domain. The wind-wave interface is modeled using the Volume-of-Fluid (VoF) method with an accurate interface capturing scheme to prevent interface diffusion. The hydrodynamic interaction between the waves and the floating solar panels are captured using a 6 Degree of Freedom Fluid-Structure Interaction model. The mooring cables are modeled by a dynamic lumped mass approach. A constraint optimization algorithm based on the Augmented Lagrangian method has been implemented to model the pivot or hinge type of connectors and the relative motion induced between the panels. From simulations of simplified floater geometry under various wind-wave conditions, it is found that the hinge connections can significantly influence the response of the floating systems, adding directional stiffness to increase the stability of the entire system, but also imposing additional complexity to the system, especially for the pitch motions of each individual floater. The complexity of each floater response is even exacerbated by the inclusion of the wind forcing, which can significantly change the dynamics of the entire system. Throughout this analysis, this approach has proven to be well-suited for further investigations on FPV systems with increasing levels of complexity. Keywords CFD, Multi Body Dynamics (MDB), Floating Photovoltaics (FPV), Fluid-Structure Interaction (FSI)