Calculation of wave forces due to extreme events in the coastal region using REEF3D - Beregning av bølgebelastninger fra ekstrem vær i kyst områder med REEF3D
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The objective of this study is to validate that the Computational Fluid Dynamics (CFD) model REEF3D can capture the singularities of the structure-wave interaction in coastal regions. The two tasks established to achieve this goal are first, the study of the slamming loads in Coastal regions and secondly, use the wave tank to simulate the wave-induced forces on a structure and validate the numerical solution by comparing it with some benchmark cases. The validation of the model is carried out by replicate five experiments that try to represent the differ-ent wave-structure interaction that we can find in the coastal region. The first experiment, that it represents a typical bridge section, it tries to assess the dependence of the elevation of a flat plate on the solitary wave-induced forces. The second case is a step further than the first case, the goal is to find also the relation between the elevation on the solitary-wave induced forces but also want to know which is the effect of adding girders on the flow. The third case is about to know the effect of the incident wave characteristic, especially the wave period, on the wave forces. The fourth case tries to describe the evolution of pressures of tsunami inundation flows around a rectangular object. The fifth case is about to try to capture the different wave stages that we can find in the coastal regions and how different are the wave forces depending on the stage of the incident wave. All the validations except the case four, that is done by simulating the pressure in the front face of the structure, are done simulating the vertical and the horizontal loads. In this master thesis, 2D and 3D analysis are carried out. In the first and the second case, the simulations are done in a 2D NWT, with a mesh size of dx=0.0025 m for all the subcases, in all of them with a remarkable agreement with the experimental data, even when slamming forces appear. The rest of the cases are simulated with a 3D NWT, this fact implies larger domains, hence with the goal of maintaining the accuracy of the solution, it needs the use of tools that allow us to reduce as much as we can the mesh size, always keeping a reasonable computational time, such as the use of the symmetry plane of the initial experimental design and the use of a non-uniform mesh in order to focus where the object is located and reduce the number of cells far from the object. The results obtained from the simulations, show us that the CFD model REEF3D is an adequate model to describe the wave-structure interaction in coastal regions.