Analysis on experimental and numerical modelling of floating structures using cfd codes

This research is focused on the study and analysis of dynamics of floating bodies. The research is carried out in two stages, an experimental process followed by a numerical process. At the first stage, Experimental tests were performed in the wave flume of the Laboratory of Hydraulic Engineering at DICAM, University of Bologna. Two prototypes of floating bodies, a cylinder and a barge, were tested for catenary and spring mooring systems under regular and irregular wave conditions. For each tested wave, the wave-structure interaction was measured by means of wave gauges and the dynamic motion of the structure is observed by means of two GOPRO cameras, recording the movement of the object from the top side of the flume and from the lateral side. The second stage is begun with an numerical analysis that is implemented by means of a numerical model which is primarily based on the Computational Fluid Dynamics (CFD). The same wave conditions as used in the experimental tests are modeled using OpenFOAM, an open source platform for CFD practices. The OpenFOAM model includes a mesh of a wave flume within which a dynamic mesh is meshed. The role of this dynamic mesh is to contain the floating body and set boundaries for the motion of the floating body. The movements of the floating body with respect to the dynamic mesh is observed. The refinement of the Meshes plays a significant role in the simulation. BlockMesh refinement plays a vital role in the simulations. The OpenFOAM model is sensitive to the refinement of the meshes, hence, the overset mesh and the primary mesh are made sure to be of the equal refinement in order to obtain an accurate result. At the end of the simulation, the experimental and numerical results from first and the second stage respectively are compared for an advance understanding of the wave-structure behavior under the given boundary conditions.