scholarly journals MODELLING WAVE-TIDE INTERACTIONS AT A WAVE FARM

2011 ◽  
Vol 1 (32) ◽  
pp. 34 ◽  
Author(s):  
Raul Gonzalez-Santamaria ◽  
Qingping Zou ◽  
Shunqi Pan ◽  
Roberto Padilla-Hernandez

The Wave Hub project will create the world’s largest wave farm off the coast of Cornwall, Southwest England. This study is to investigate wave and tide interactions, in particular their effects on bottom friction and sediment transport at the wave-farm coast. This is an ambitious project research which includes the use of a very complex numerical modelling system. The main question to answer is how waves, tidal currents and winds affect the bottom friction at the Wave Hub site and the near-shore zone, as well as their impact on the sediment transport. Results show that tidal elevation and tidal currents have a significant effect on the wave height predictions, tidal forcing and wind waves have a significant effect on the bed shear-stress, relevant to sediment transport, waves via radiation stresses have an important effect on the long-shore and cross-shore velocity components, particularly during the spring tides, waves can impact on bottom boundary layer and the mixing in the water column. Interactions between waves and tides at the Wave Hub site is important when modelling coastal morphology influenced by wave energy devices, this open-source modelling system tool will help the study of physical impacts on the Wave Hub farm area.

2012 ◽  
Vol 1 (33) ◽  
pp. 66 ◽  
Author(s):  
Raul Gonzalez ◽  
Qingping Zou ◽  
Shunqi Pan

This paper presents the results from an integrated modelling system investigating the effects of a wave farm on nearshore sediment transport. Wave Hub project is a large scale demonstration site for the development of the operation of arrays of wave energy generation devices located at the southwest coast of the UK where multiple field measurements took place. The two-way coupled SWAN and ROMS models with nested modelling system were set up at the Wave Hub site and run with and without a wave farm. The model results show that the presence of the wave farm has significant impacts on the nearshore circulation, bed shear stresses and sediment transport. The morphological changes are also altered by the wave farm. The study is the key element for the wave resource characterization and environmental impact assessment of the wave farm.


1995 ◽  
Vol 32 (2) ◽  
pp. 77-83
Author(s):  
Y. Yüksel ◽  
D. Maktav ◽  
S. Kapdasli

Submarine pipelines must be designed to resist wave and current induced hydrodynamic forces especially in and near the surf zone. They are buried as protection against forces in the surf zone, however this procedure is not always feasible particularly on a movable sea bed. For this reason the characteristics of the sediment transport on the construction site of beaches should be investigated. In this investigation, the application of the remote sensing method is introduced in order to determine and observe the coastal morphology, so that submarine pipelines may be protected against undesirable seabed movement.


Ocean Science ◽  
2017 ◽  
Vol 13 (5) ◽  
pp. 673-690 ◽  
Author(s):  
Guilherme Franz ◽  
Matthias T. Delpey ◽  
David Brito ◽  
Lígia Pinto ◽  
Paulo Leitão ◽  
...  

Abstract. Coastal defence structures are often constructed to prevent beach erosion. However, poorly designed structures may cause serious erosion problems in the downdrift direction. Morphological models are useful tools to predict such impacts and assess the efficiency of defence structures for different scenarios. Nevertheless, morphological modelling is still a topic under intense research effort. The processes simulated by a morphological model depend on model complexity. For instance, undertow currents are neglected in coastal area models (2DH), which is a limitation for simulating the evolution of beach profiles for long periods. Model limitations are generally overcome by predefining invariant equilibrium profiles that are allowed to shift offshore or onshore. A more flexible approach is described in this paper, which can be generalised to 3-D models. The present work is based on the coupling of the MOHID modelling system and the SWAN wave model. The impacts of different designs of detached breakwaters and groynes were simulated in a schematic beach configuration following a 2DH approach. The results of bathymetry evolution are in agreement with the patterns found in the literature for several existing structures. The model was also tested in a 3-D test case to simulate the formation of sandbars by undertow currents. The findings of this work confirmed the applicability of the MOHID modelling system to study sediment transport and morphological changes in coastal zones under the combined action of waves and currents. The same modelling methodology was applied to a coastal zone (Costa da Caparica) located at the mouth of a mesotidal estuary (Tagus Estuary, Portugal) to evaluate the hydrodynamics and sediment transport both in calm water conditions and during events of highly energetic waves. The MOHID code is available in the GitHub repository.


2013 ◽  
Vol 718-720 ◽  
pp. 371-376
Author(s):  
Yin Cai ◽  
Meng Guo Li ◽  
Ming Xiao Xie

Based on a series of multi-source satellite remote sensing imageries and wind parameters extracted from QuickSCAT satellite datasets, the surface suspended sediment concentrations (SSC) of the Zhuanghe coastal area, China was investigated using the retrieval technique. The results showed that the SSC of the Zhuanghe coastal area is higher in the nearshore zone, and gradually diminishes to the offshore. During the ebbing process, the range of high SSC zone is wider than that during the flooding process. This feature indicated that the suspended sediment transport is mainly determined by the ebb currents, and the sediment source comes from the nearshore shallow flats, where the sediments could be entrained by the wind waves and then diffuses offshore or alongshore with the tidal currents.


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