This work investigates wave reflection and loading on a generalised Oscillating Water Column (OWC) wave energy converter by means of large scale (approximately 1:5-1:9) experiments in the Grosse Wellenkanal (GWK), in which variation of both still water depth and orifice (PTO) dimension are investigated under random waves. The model set-up, calibration methodology, reflection analyses and loadings acting on the OWC are reported.On the basis of wave reflection analysis, the optimum orifice is defined as that restriction which causes the smallest reflection coefficient and thus the greatest wave energy extraction. Pressures on the front wall, rear wall and chamber ceiling are measured. Maximum pressures on the vertical walls, and resulting integrated forces, are compared with available formulations for impulsive loading prediction, which showed significant underestimation for The present study demonstrates that a OWC structure can serve as a wave absorber for reducing wave reflection. Thus it can be integrated in vertical wall breakwaters, in place of other perforated low reflection alternatives. The possibility to convert air kinetic into electric energy, by means of a turbine, may give an additional benefit. Thus the installation of such kind of energy converters becomes interesting also in low energy seas.

a b s t r a c tThe objective of this paper is to provide a synthetic tool for determining expeditiously the wave climate conditions in several areas of the Mediterranean Sea. In the open literature, several authors have already conducted this specific analysis also for the area under examination in this paper. However, the need of discussing aspects strictly related to the design of wave energy harvesters is still relevant. Therefore, considering the variety of devices and the amount of information needed for conducting both an energywise optimization and a structural reliability assessment, a holistic view on the topic is provided. Specifically, the paper elucidates the theoretical aspects involved in the estimation of wave energy statistics and in the calculation of relevant return values. Next, it provides synthetic data representing the mean wave power and the return value of extreme events in several coastal areas of the Mediterranean Sea. In this regard, the paper complements information available in the open literature by discussing the influence of the directional pattern of the sea states in the determination of sea state statistics as well as in the design of a wave energy harvester.

A feasibility study for installing Wave Energy Converters (WECs) in a Mediterranean port is presented here. The final aim is to evaluate the possibility of building a green touristic infrastructure in a site having ordinary wave energy. In particular, the site of interest is Giardini Naxos, which is located in the northern Ionian coast of the island of Sicily (Italy). A preliminary estimation of the available energy has been carried out. The chosen type of WEC device is the Oscillating Water Column (OWC) system, which is found here to allow for good integration with the vertical breakwater needed for the extension of the existing port. Its feasibility is evaluated from the structural and economic point of view. Towards this aim, the system is tested in the laboratory for estimating the reflection coefficients and the pressures on the structure, which allow us to carry out the optimization of the OWC breakwater. Furthermore, the air turbine noise is estimated and an attenuation chamber is designed to reduce such noise to within acceptable levels. The economic feasibility study allows for an evaluation of the recuperation period of the investment, which is slightly less than the service life of the WEC device.

The propagation of gravity currents is analyzed in the presence of regular surface waves, 5 both experimentally and numerically, by using a full-depth lock-exchange configuration. Full- hydrodynamics of the density current is significantly affected by the presence of the wave 12 motion. In particular, the front shows a pulsating behavior, the shape of the front itself is

Aim of the present work is to contribute to the knowledge about the interaction between the flow induced by waves and the aquatic vegetation. More in details, the results of preliminary tests of an experimental laboratory investigation about the response of a Posidonia Oceanica meadow to wave motion in shallow waters is reported. A wide attention was posed to the behavior of a synthetic plants with plastic material. To this aim an image acquisition technique was used to analyze and compare the movement of both the artificial plant and the real one. The experiments carried out about the interaction between the artificial meadow and the waves showed a significant wave dumping, in particular in the case of plants having the same length of the water depth.