3D Numerical Model Of Multi-fraction Sediment Transport And Its Application

It is very common for harbor and coastal engineering to deal with the coastal evolution and the channel siltation problems induced by the sediment transport. So it is of great importance to develop a numerical model of sediment transport under the effects of complicated hydrodynamic conditions. Therefore, a 3D numerical model for multi-fraction sediment transport under the combined action of wind, wave and current is developed and applied in the Weifang Harbor in the present thesis.The 3D model of EFDC and the SWAN wind wave model are firstly introduced for the coupled simulation of the wind wave filed and the flow field. To improve the accuracy and the speed of simulation, the 3D flow computation is nested in the 2D model, and the wind wave simulation also adopts big, middle and small nested mode. The 3D numerical model for multi-fraction sediment transport is used to simulate sediment transport. Combining wind wave, current and the sediment model together, the sediment transport model under the combined action of wind, wave and current is developed.The developed model is applied to simulate the sediment transport and the geomorphologic evolution around Weifang Harbor. The simulated results of flow and sediment transport are verified by the measured data in site. Numerical results show that the sediment transport along the silt coast can be described well by the model, and the influence of harbor structure on the flow field and bed erosion and deposition around itself are successfully disclosed.