Swan and its recent developments (poster)

The SWAN model is a third-generation spectral wave prediction model developed by Delft University of Technology. Since its initial release in 1998 this model has become a widely used and reliable tool for offshore and near shore wave predictions. Its main field of application is the coastal zone where, by virtue of its implicit numerical scheme,...

Non-hydrostatic modelling of infragravity waves using swash

This paper presents numerical modelling of the nearshore transformation of infragravity waves induced by bichromatic wave groups over a horizontal and a sloping bottom. The non-hydrostatic model SWASH is assessed by comparing model predictions with analytical solutions over a horizontal bottom and with detailed laboratory observations for a...

Topography-induced focusing of random waves

Refraction of narrow-band surface waves in coastal areas can result in wave-focal zones where due to interference, wave statistics vary rapidly and on similar length scales as those of individual waves. However such interference patterns, or wave coherence, are not accounted for in conventional stochastic wave models that are based on the energy...

Topography-induced focusing of random waves

Refraction of narrow-band surface waves in coastal areas can result in wave-focal zones where due to interference, wave statistics vary rapidly and on similar length scales as those of individual waves. However such interference patterns, or wave coherence, are not accounted for in conventional stochastic wave models that are based on the energy...

Non-hydrostatic modelling of infragravity waves using SWASH

This paper presents numerical modelling of the nearshore transformation of infragravity waves induced by bichromatic wave groups over a horizontal and a sloping bottom. The non-hydrostatic model SWASH is assessed by comparing model predictions with analytical solutions over a horizontal bottom and with detailed laboratory observations for a...

Simulating nearshore wave transformation with non-hydrostatic wave-flow modelling

Coherent interference and diffraction in random waves

Wave fields traveling through a varying medium (e.g. topography, currents), can develop well-defined focal zones and caustics, where the wave field is highly coherent and wave statistics vary rapidly. However, the presence and evolution of such coherent structures in the wave field are not resolved in a quasi-homogeneous description of the wave...

What determines nearshore sandbar response?

Nearshore sandbars appear with various patterns which may change over time. From observations, these changes seem to be related to changes in hydrodynamic conditions, although observed length scales could not be related directly to occurring wave conditions. The current work investigated the role of both the concurrent and previous hydrodynamics...

Optimization of maintenance for power system equipment using a predictive health model

In this paper, a model-predictive control based framework is proposed for modeling and optimization of the health state of power system equipment. In the framework, a predictive health model is proposed that predicts the health state of the equipment based on its usage and maintenance actions. Based on the health state, the failure rate of the...

Dielectric interfaces in DC constructions: Space charge and polarization phenomena

Interfaces between dielectrics are considered one of the weakest parts of an insulation system but their behavior under electrical stress is not yet completely understood. In particular, when a dc voltage is applied, the electric field distribution at the interface is quite difficult to predict. This is mainly due to the accumulation of internal...

Calculation and measurement of space charge in MV-size xxtruded cables systems under load conditions

A load current in dc high voltage cables results in a temperature drop across the insulation and hence a radial distribution of the insulation conductivity is found. Direct consequence is an accumulation of space charge in the bulk of the nsulation, that may significantly affect its reliability. This phenomenon was modeled in terms of the...

Insulation Diagnosis of High Voltage Power Cables

Decision support for maintenance managent of high voltage components

Comparison of the breakdown strength of N2, CO2 and SF6 using the extended up-and-down method