Use of impulses to determine the reaction force of a hydraulic structure with an overhang due to wave impact

This paper describes a method of determining the reaction forces of a vertical structure with an overhang to impulsive wave impacts. The aim is to develop a method to design a hydraulic structure exposed to the impulsive wave impact. At present, there is a lack of guidelines on the designing and verification with such a purpose. The impulse...

Wave transmission at low-crested structures using neural networks

The European Union funded project DELOS was focused on wave transmission and an extensive database on low-crested rubble mound structures was generated. During DELOS, new empirical wave transmission formulae were derived. These formulae still showed a considerable scatter due to a limited number of parameters included. Neural networks based on a...

Final report on generic prediction method of wave overtopping

Within the framework of the European project CLASH phenomena related to wave overtopping are studied. In this report a method to predict wave overtopping at a wide range of coastal structure types is given. The method is based on Neural Network modelling of the mean wave overtopping discharge. The method can be applied for coastal structures...

Neural network manual for NN_Overtopping program

Following this general introduction, Chapter 2 provides the structure of the program and the description of the parameters involved in the prediction tool. Then, Chapter 3 provides an explanation of the estimation and schematisation of the hydraulic and structure parameters. Finally, Chapter 4 describes the use of NN_OVERTOPPING 2, including: i....

Influence of low-frequency waves on wave overtopping; a study based on field measurements at the Petten Sea-defence

Within the framework of the European project CLASH phenomena related to wave overtopping are studied. One of the topics that require further attention is the influence of low-frequency waves on wave overtopping. Here, use is made of field measurements performed at the Petten Sea-defence (by Rijkswaterstaat and made available by RIKZ) and...

Numerical modelling of wave interaction with dynamically stable structures

Wave interaction with dynamically stable structures is simulated by means of a numerical model based on fmite-amplitude shallow-water wave equations. The model can simulate wave motion on and inside permeable structures. For dynamically stable structures, including berm breakwaters, reef-type structures and gravel beaches, a procedure is...

Wave interaction with berm breakwaters

Wave interaction with berm breakwaters is studied by means of a physical model and a numerical model. The physical-model tests have been used to verify the wave motion as calculated by the numerical model. The numerical model based on finite-amplitude shallow-water wave equations is capable of simulating the wave motion both on and inside the...

Berm breakwater structures: Numerical simulation of breaking waves

A two-dimensional numerical model that can simulate plunging waves on permeable structures is described. The 'Volume Of Fluid' method is used to solve the incompressible Navier-Stokes equations (2DV). This enables simulations with very complex shapes of the free surface like those occurring in breaking waves. The model has been extended with...

Berm breakwaters; hydrodynamics, forces and profile-development

The wave motion on-and-in Berm breakwaters as well as the reshaping process have been studied. Measurements were carried out to study wave interaction with a reshaped Berm breakwater. These tests were used for verification of a numerical model capable of simulating both the wave motion on as well as inside the structure. This numerical model has...

Stationary and oscillatory flow through coarse porous media

Measurements in a U-tube tunnel were carried out to study flow through coarse granular material. Tests with stationary flow and tests with oscillatory flow were done to study the differences between both. The coefficients from the extended Forchheimer equation, which is supposed to describe non-stationary porous flow, were determined. It...

Numerical model for wave action on and in coastal structures

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...

Formulae to describe porous flow

For the description of porous flow the Forchheimer equation is normally used. Several formulae have been proposed for the coefficients Cl and c2 from this equation. All these formulae are based on experiments. Those coefficients represent the friction and resistance caused by the porous medium. The Forchheimer equation is a somewhat semi...