Lisanne Braat

The main objective of this research is to determine the relative influence of tides, waves and wind on the generation of current around the sand motor by hydrodynamic modelling. Hydrodynamic modelling is an essential step in predicting future morphologic change of the sand motor and to determine its efficiency. D-flow Flexible Mesh is used for hydrodynamic simulations. In this research this new software is used with the goal to improve hydrodynamics modelling results and additionally provide a test case for this new software. Different grids are developed and used to study the effect and efficiency of unstructured modelling. To analyse the influence of waves a coupling is made with the new unstructured wave module, UNSWAN, of which the first version will be released in July 2014. The research is therefore also a pilot study using D-Flow FM and UNSWAN coupling.

Figure, 1) curvilinear grid, 2) flexible mesh based on grid 1 with refined and derefined areas, 3) flexible mesh with curvilinear grid band following the coastline.

Main question: “What are the relative effects of tides, waves and wind on currents around the sand motor?”

Sub-questions:
“Does (unstructured) modelling with the use of D-Flow Flexible Mesh improve hydrodynamics modelling results, and to which extend?”
“What is the effect of modelling with an unstructured grid / flexible mesh?”
“How can unstructured grids be used efficiently?”
“What are the implications of currents generated by tides, waves or wind?”