Ricerc@Sapienza

We present a study of wave overtopping of barriers. The phenomenon of the wave overtopping over emerged structures is reproduced both numerically and experimentally. The numerical simulations are carried out by a numerical scheme for three-dimensional free-surface flows, which is based on the solution of the Navier-Stokes equations in a novel integral form on a time-dependent coordinate system. In the adopted numerical scheme, a novel wet-dry technique, based on the exact solution of the Riemann problem over the dry bed, is proposed.

The function of main port breakwaters is to protect harbour basins from incoming waves and currents. In the event that a maritime terminal is placed on the inner side of a main breakwater, it is extremely important to limit waves overtopping the structure, because the overtopping flows may be very dangerous for the safety of the operations taking place in the terminal. Very often during storms if the overtopping discharges are severe, the terminal is temporarily closed, reducing its average annual workability accordingly.

This work presents the results of an experimental investigation on the effects of a sequence of storms on wave overtopping at a nearly vertical battered seawall at the back of a sandy foreshore. The experiments were carried out in the Large Wave Flume (GWK) at Leibniz Universität Hannover (Germany), as part of the research project ICODEP (Impact of Changing fOreshore on flood DEfence Performance), within the European Union programme Hydralab+. The layout consisted of a 10/1 battered seawall and a natural sandy foreshore with an initial 1:15 slope.