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The problem of water shipping is studied by assuming two-dimensional flow conditions and using both experimental and numerical tools. Experimentally, the water on deck for a fixed barge-shaped structure has been analysed. Video images of the water-shipping events were recorded, wave elevation in the wave flume and pressure on a vertical superstructure along the ‘ship’ deck have been measured. Numerically, a boundary element method for unsteady nonlinear free-surface flows was developed and used for the analysis of water-on-deck phenomena. A comprehensive comparison between experimental and numerical data gave satisfactory agreement globally. The synergic experimental–numerical analysis highlights the main flow features during the water shipping and details of the water impact with the deck structures are discussed. In the model tests, the water on deck started as a plunging wave hitting the deck and entrapping air. This could be relevant for deck safety, but appears to be less important for the global evolution of the water along the deck and the later liquid interaction with the superstructure. The green-water loads on the vertical wall showed a two-peak behaviour typical of wave impacts.

The generation and evolution of two-dimensional bores in water of uniform depth and on sloping beaches are simulated through numerical solution of the Euler equations using the smoothed particle hydrodynamics (SPH) method, wherein particles are followed in Lagrangian fashion, avoiding the need for computational grids. In water of uniform depth, a piston wavemaker produces cyclically breaking bores in the Froude number range 1.37–1.82, which were shown to move at time-averaged speeds in very good agreement with the requirements of global mass and momentum conservation. A single Strouhal number for the breaking period was discovered. Complex repetitive splashing patterns are observed and described, involving forward jet formation growth, impact and ricochet, and similarly, backward jet formation and impact. Observed consequences were the creation of vortical regions of both signs, dipole creation through pairing, large-scale transport of surface water downward and high tangential scouring velocities on the bed, which are quantified. These bores are further allowed to rise on linear slopes to the shoreline, where they are seen to collapse into a tongue-like flow resembling dam-break evolution.This essentially inviscid calculation is able to reproduce the development of a highly vortical flow in excellent agreement with experimental observations and theoretical concepts. The turbulent flow behaviour is partially described by the numerical solution.

A numerical method is developed for modeling the violent motion and fragmentation of an interface between two fluids. The flow field is described through the solution of the Navier-Stokes equations for both fluids (in this case water and air), and the interface is captured by a Level-Set function. Particular attention is given to modeling the interface, where most of the numerical approximations are made. Novel features are that the reintialization procedure has been redefined in cells crossed by the interface; the density has been smoothed across the interface using an exponential function to obtain an equally stiff variation of the density and of its inverse; and we have used an essentially non-oscillatory scheme with a limiter whose coefficients depend on the distance function at the interface. The results of the refined scheme have been compared with those of the basic scheme and with other numerical solvers, with favorable results. Besides the case of the vertical surface-piercing plate (for which new laboratory measurements were carried out) the numerical method is applied to problems involving a dam-break and wall-impact, the interaction of a vortex with a free surface, and the deformation of a cylindrical bubble. Promising agreement with other sources of data is found in every case.