The modelling of wave action on and in coastal structures

Description of the wave action on and in coastal structures can lead to a prediction of flow properties and forces on elements of those structures. For permeable structures several aspects concerning the interaction between the external flow and the internal flow have to be described accurately to predict for instance velocities and run-up levels. The P.C.-model ODIFLOCS, developed at Delft University of Technology within the framework of the European MAST-Coastal Structures project, describes the wave motion on and in several types of structures. This structure can be an impermeable or a permeable structure. For instance dikes, breakwaters and submerged structures can be dealt with. The model is a one-dimensional model based on long wave equations. The program takes various phenomena into account such as reflection, permeability, infiltration, seepage, overtopping, varying roughness along the slope, linear and non-linear porous friction (Darcy- and turbulent friction), added mass, internal set-up and the disconnection of the free surface and the phreatic surface. Satisfactory results were obtained with modelling of run-up, surface elevations and velocities. Other applications show more possibilities of the model.