Numerical investigation of local scour around rubble mound breakwater under the wave effect

Current characteristics caused local scour due to configuration of rubble-mound breakwaters which are constructed for various port structures. Erosion of the seabed material which leads to stability losses or even failure, has great importance for the equilibrium of these structures. The objective of this thesis is to gain insight about growth of erosion patterns. Within the scope of the thesis, a numerical wave flume with 33 m length, 3.6 m width and 1.2 m depth was used to observe wave-induced local erosion at the toe of sloped rubble mound breakwaters. Regular and irregular (JONSWAP) waves were generated by using Flow3D, one of the advanced computational fluid dynamics (CFD) programs. A numerical model was conducted with different variables (different slope angles, different bed materials and different wave characteristics). Scour patterns were investigated for seabed materials with 1 mm, 0.55 mm and 0.20 mm grain median diameters under various wave scenarios and breakwater slopes 2:3 and 1:2 which are widely used in construction. In these scenarios, the breakwater features are also defined as porous and rip-rap layer. In order to validate the numerical model, the results of the experiments carried out in the physical wave channel of Dokuz Eylül University Civil Engineering, with 1.85 mm diameter seabed material and 2:3 sloped breakwater were compared with the numerical model results, under the same wave conditions. From the results obtained from the study were interpreted, it is understood that the performance of the numerical model was found to be high and the model was accurate.