Print Email Facebook Twitter 2D and 1D numerical model simulations for the effect of a single detached breakwater on the shore Title 2D and 1D numerical model simulations for the effect of a single detached breakwater on the shore Author Ahmed, A.S.M. Contributor Van Rijn, L.C. Verhagen, H.J. Bos, K.J. Corporate name Rijkswaterstaat Project KWP-collection Date 1997-06-01 Abstract The developmeot of the coastal area is oeeded for tourism and commercial purposes for a country located nearby a coast. Coastal development may lead to local erosion of the shoreline. Coastal defence structures, like an offshore breakwaters, may be used to solve tbis problem. An offshore breakwater is a breakwater parallel to the shore and located at aspecific distance form the original shoreline. To understand the influence of the breakwater on the hydrodynamic processes as well as on the morphological evolution, physical models or mathematical models are developed. The mathematical models do not suffer from the scale effect. In this study, a morphodynamic model DELFI'2D-MOR, which is a two-dimensional horizootal model, and an ooe-line model UNIBEST have been used. The DELFI'2D-MOR model is a coupled model system which coosists of four modules. The four modules are the wave module (lllSW A), the flow module (TRISULA), the transport module and the bottom module. A sensitivity analysis is made to investigate the impact of the offshore breakwater geometry on the hydrodynamic processes and the morphological evolutions. It was found that the breakwater geometry affects the hydrodynamic processes as well as the morphological evolution (salient or tombolo). Based on sensitivity analysis, the wave-current interaction was found to affect the morphological evolutions. The agreement between the results of the model and the literature results was quite satisfactory. After getting insight in the validity of the DELFI'2D-MOR model, a case study of a single detached breakwater situated at the northern coast of Egypt was carried out. The wave elimate was analyzed to get the morphological equivalent one-wave condition and two-wave condition. The choice of the bottom roughness in the one-wave condition simulation appeared to affect the hydrodynamic processes and the morphological evolutions. Applying the twowave condition in the 2D-computations gave a step forward for the morphological computations in which the two-wave condition simulation gave more authentic results than the one-wave condition simulation. The choice of the wave-current induced shear stress appeared to affect the hydrodynamic processes in the 2D-model. The results of wave, longshore current and the sediment transport in the UNIBEST model are compared to the 2D-model results. It was found that the longshore current was higher due to the longshore current formulation used in the UNIBEST model. This in turn affects the sediment transport rate. Tombolo formation can not be simulated in the UNIBEST model for a case with normally incident waves since the effects of the circulation cells are not taken into account. However, it can be simulated for a case with obliquely incident waves. Subject detached breakwatercoastal morphology Classification TPG210150 To reference this document use: http://resolver.tudelft.nl/uuid:6d682f66-c15a-465c-887d-3df3009da0e2 Publisher Deltares (WL) Source Q1800.22 Report Delft Hydraulics - IHE MSc thesis in cooperation with Delft Hydraulics Part of collection Hydraulic Engineering Reports Document type report Rights © 1997 Ahmed Sayed Mohamed Ahmed Files PDF Ahmed1997.pdf 55.73 MB Close viewer /islandora/object/uuid:6d682f66-c15a-465c-887d-3df3009da0e2/datastream/OBJ/view