Hydrodynamic loading of breaking waves on offshore inspection platforms

The most violent breaking waves cause the largest platform forces at sea, however it is unknown which wave in a sea state leads to these forces if run-up is included. Offshore inspection platforms give access to wind turbine monopiles. They are positioned above mean sea level. Wave interaction with monopiles leading to runup causes vertical...

Breaking wave impacts on the front deck of a ship: An experimental and numerical study about green water on ships in focused breaking waves

Green water events on ships in extreme waves pose a considerable risk to personal, operational, and structural safety. Considering these issues, novel experiments were done to investigate the interaction between focused breaking waves and a ship at forward speed. The investigated interactions are global motion, global loads, and forces on a deck...

Stability of stones in the surf zone

Much research has been done on the stability of stones in breaking waves, but up to now, most of these studies were based on experiments with slopes varying from 1: 1 to 1:7. The stability of stones on mild slopes, slopes not steeper than 1: 10, has not yet been researched very extensively. Applications of mild slopes in practice are for example...

The influence of breaking waves on the vertical velocity distribution in the surf zone

In this report we describe the development and calibration of a model which predicts the vertical distribution of the horizontal velocities induced by waves, the so-called undertow. Location of interest is the nearshore region where the flow is induced by both breaking and non-breaking waves. The model consists out of three modules. The first...

Non-Hydrostatic Computations of Nearshore Hydrodynamics

The nearshore zone is an active zone that can be quite inhospitable to humans due to violent wave breaking and strong rip currents. Rip currents are shore normal jet-like currents that typically extend from near the shoreline out past the line of breaking waves. Observations have concluded that a rip current system generally consists of 4 parts....

Wave impact on grass covered outer slopes

Against the background of enhanced hydraulic loads due to climate change there will be a need for improvement of the flood defence system in the Netherlands in the future. These days there is a growing interest in grass as a dike cover because it is a cheap and a sustainable dike protection. Yet at the moment there is a hiatus in the knowledge...

The breaking of windwaves in deep water: Part I. Probalistic aspects : Part II. Observed breaking wave statistics

Part I Probabilistic aspects. An overview is given of literature on the statistics of breaking waves in open ocean. New approximations of the fraction of breaking waves and the distribution of breaking wave heights are presented and compared with results found in literature. Part II Observed breaking wave statistics. This part is dedicated to...

Golfvervorming bij een hoog voorland

Het rapport "Literatuuronderzoek bij een hoog voorland" bevat een systematische weergave van de bestaande kennis van het gedrag van golven in een bepaalde ondiepte-situatie. Die situatie betreft een tamelijk vlak, relatief hoog liggend voorland voor een kust met daar boven een geringe waterdiepte, en wel het gebied vanaf de lijn waar de golven...

Generation of low-frequency waves due to obliquely incident grouped short waves

Looking at a surfzone, one immediately notices the short breaking waves. Looking more carefully, will show in most cases that the wave height of the breaking waves is not constant, but varies in time. Often one may observe that groups of relatively high waves are followed by groups of lower waves. This short wave groupiness may cause low...

Wave slamming forces on truss structures for wind turbines

Generally the foundations of offshore wind turbines are steel truss structures which are exposed to wave slamming forces due to breaking waves, typically plunging breaking waves in shallow water. Calculations show that the forces from the plunging breaking waves are governing the design responses of the structure and the foundations. However,...

Experimental Measurements of Wave Impacts in a Breaking Dam Flow: An Application of Computer Vision for Quantitative Reconstruction of the Free Surface in Breaking Waves

Breaking water waves still represent a very active research area, as they are involved in a broad spectrum of situations ranging from safety at sea to climate change. The detailed knowledge of the location of the free surface in case of breaking waves or wave impacts could prevent structural damages, increase the efficiency of ship hulls and...

Study of the diffusion activity in case of non-breaking waves with a current

Sediment transport causes morphological changes of coastal areas, and it is one of the most important objects in coastal engineering study. Recently, various experiments have been performed to investigate the sediment transport mechanism under a combination of waves and currents and to find the underlying relationships among various parameters...

Wave loads on vertical walls: Validation of design methods for non-breaking waves of bimodal spectra

During the design process of the new sea lock in IJmuiden the design wave conditions were described by a bimodal wave spectrum. With a spectral calculation method it was observed that a small low frequency component leaded to a large influence in the force spectrum. This observation served as the starting point for this thesis, where different...

Analysis of elastoplastic response of maritime structures in breaking waves using a double pendulum with a friction hinge

Waves impacting on maritime structures can cause damage which endangers the environment around these structures. Due to high hydrodynamic loading, structures can enter the plastic regime, resulting possibly in structural failure. The understanding of the principles related to this structural failure due to waves is a key concept in this research...

Mastering Breaking Waves in the Multiphase Wave Lab at MARIN

Wave impact tests are performed in the LNG industry to design the structure of the cargo containment system (CCS) of the vessels and to study the physics of breaking wave impacts. The state-of-the-art methodology divides the wave impact flow into two parts: the global flow and the local flow. The global flow considered as the solution of the...

Effect of bed roughness on the hydrodynamic properties of dam-break waves

A dam-break wave can result in considerable damages and casualties. Events that can lead to such waves include dike and dam breaches, storm surges and impulse waves. Dutch history is familiar with a number of coastal dike breaches but also river dike breaches have occurred, resulting in dam-break waves reaching far inland. Beyond the Netherlands...

Wave breaking induced drift: An experimental and theoretical prediction in deep-water waves

Accurately predicting the surface transport in the ocean is crucial for estimating the course of marine pollution, which is considered one of the most pressing environmental issues of the 21st century. In the ocean, floating marine pollution is transported by several mechanisms, including waves. Current models predicting the surface transport...

Numerical estimation of wave loads on crest walls on top of rubble mound breakwaters using OpenFOAM

The design of hydraulic structures like breakwaters and crest walls is often based on empirical formulations, physical models test, numerical models and a fair amount of expert judgement. Each technique has its own pros and cons. The main limitation of the empirical formulas is that often they have to be applied outside their range of validity....