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.

Aim of the present work is to contribute to the knowledge about the interaction between the flow induced by wave 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.

The propagation of gravity currents is analyzed in the presence of regular surface waves, both experimentally and numerically, by using a full-depth lock-exchange configuration. Full-depth lock-exchange releases have been reproduced in a wave flume, both in the absence and in the presence of regular waves, considering two fluids having densities ${\rho }_0$ and ${\rho }_1$ , with ${\rho }_0<{\rho }_1$ . Boussinesq gravity currents have been considered here (${\rho }_0/{\rho }_1\sim 1$ ), with values of the reduced gravity $g^{\prime }$ in the range $0.01–0.1\mathrm{m}/{\mathrm{s}}^2$ , while monochromatic waves have been generated in intermediate water depth. The experimental results show that the hydrodynamics of the density current are significantly affected by the presence of the wave motion. In particular, the front shows a pulsating behavior and the shape of the front itself is less steep than in the absence of waves, while turbulence at the interface between the two fluids is damped out. In the present test conditions, the average velocity of the advancing front may be decreased in the presence of the combined flow as a function of the relative importance of buoyancy compared with wave-induced Stokes drift. Moreover, a new numerical model is proposed, aiming at obtaining a simple, efficient, and accurate tool to simulate the combined motion of gravity currents and surface waves. The model is derived by assuming that surface waves are not affected by gravity current propagation at the leading order and that the total velocity field is the sum of velocities forced by the orbital motion and those forced by buoyancy. A Boussinesq-type wave model for nonstratified fluids is solved, and its results are used as input of a gravity current model for stratified flows. Comparisons of the numerical results with the present experimental data demonstrate the capability of the model to predict the main features of the analyzed phenomena concerning propagation of the density current (e.g., averaged velocities, front height), the increase of entrainment of the ambient fluid into the density current in the presence of the waves, and the intrawave pulsating movement of the heavy front.