The influence of directional spreading on rogue waves triggered by abrupt depth transitions

An increased number of rogue waves, relative to standard distributions, can be induced by unidirectional waves passing over abrupt decreases in water depth. We investigate this phenomenon in a more general setting of multidirectional waves. We examine the influence of the directionality on the occurrence probability of rogue waves using...

A nonlinear, non-dispersive energy balance for surfzone waves: Infragravity wave dynamics on a sloping beach

A fully nonlinear non-dispersive energy balance for surfzone waves is derived based on the nonlinear shallow water equations to study the nearshore dynamics of infragravity (IG) waves. Based on simulations of waves on a relatively moderate and mild beach slope with a non-hydrostatic wave-flow model (SWASH), the new theory shows that spatial...

Wave breaking and jet formation on axisymmetric surface gravity waves

Axisymmetric standing waves occur across a wide range of free surface flows. When these waves reach a critical height (steepness), wave breaking and jet formation occur. For travelling surface gravity waves, wave breaking is generally considered to limit wave height and reversible wave motion. In the ocean, the behaviour of directionally...

Why rogue waves occur atop abrupt depth transitions

Abrupt depth transitions (ADTs) have recently been identified as potential causes of 'rogue' ocean waves. When stationary and (close-to-) normally distributed waves travel into shallower water over an ADT, distinct spatially localized peaks in the probability of extreme waves occur. These peaks have been predicted numerically, observed...

MNLS simulations of surface wave groups with directional spreading in deep and finite depth waters

We simulate focusing surface gravity wave groups with directional spreading using the modified nonlinear Schrödinger (MNLS) equation and compare the results with a fully-nonlinear potential flow code, OceanWave3D. We alter the direction and characteristic wavenumber of the MNLS carrier wave, to assess the impact on the simulation results....

A mechanism for the increased wave-induced drift of floating marine litter

Periodic water waves generate Stokes drift as manifest from the orbits of Lagrangian particles not fully closing. Stokes drift can contribute to the transport of floating marine litter, including plastic. Previously, marine litter objects have been considered to be perfect Lagrangian tracers, travelling with the Stokes drift of the waves....

Modelling statistical wave interferences over shear currents

Wave forecasting in ocean and coastal waters commonly relies on spectral models based on the spectral action balance equation. These models assume that different wave components are statistically independent and as a consequence cannot resolve wave interference due to statistical correlation between crossing waves, as may be found in, for...

Wave power extraction from multiple oscillating water columns along a straight coast

The integration of oscillating water column (OWC) wave energy converters into a coastal structure (breakwater, jetty, pier, etc.) or, more generally, their installation along the coast is an effective way to increase the accessibility of wave power exploitation. In this paper, a theoretical model is developed based on the linear potential flow...

Resonance characteristics of tides in branching channels

Numerical harbour simulations with the model TRIWAQ - NH: With an emphasize on the present reflective properties

The focus is on the numerical flow model TRIWAQ. It is developed as a hydrostatic free-surface flow model, which is currently being used by the KNMI and Rijkswaterstaat for predictions of water levels in the North Sea and Dutch estuaries. TRIWAQ has successfully been extended to the realm of nonhydrostatic modeling, TRIWAQ-NH, this allows the...