Chapter 1
1.
Introduction.
In the MAST-G6-S program numerical models will be developed for the description of wave motion on and in coastal structures. The most accurate one will probably be the SKYLLA model. That model uses the two-dimensional Navier-Stokes equations. For a description, see Broekens and Petit (1991). After it has been developed for structures with an impermeable slope (dikes), the porous flow has to be implemented for application for permeable structures. Adapted Navier-Stokes equations for the modelling of the porous flow are described by Van Gent (1991). The implementation of the porous flow is important for rubble mound breakwaters and Berm-breakwaters because there is an important interaction between the flow on the structure and the flow in the structure.
Parallel to the development of the SKYLLA model, other models will be developed within the MAST-G6-S program. These models have to describe the flow on and in coastal structures. This means that a hydraulic model has to be coupled to a porous flow model. This will be done in a way so that the model can be used as an "Engineering Tool". The model described in this report is based on a one dimensional description of the flow (which does not mean that it can not give a two-dimensional impression of the flow). It means that the model uses some simplifications that make the results of the model deviate from reality but in such a way that the results do not deviate too much and will give a rather good impression of the movement of the water on and in a coastal structure.
