Experimental study of breaking wave flow field past a submerged hydrofoil by LDV

In the present work the free surface flow past a submerged hydrofoil was studied by experimental techniques. The purpose of this experiment, carried out in a water circulating channel, was to investigate the flow field concerned with the steady 2-D breaking wave. Free surface profiles were measured by a conventional wave probe, while the velocity field was obtained by LDV, both in nonbreaking and breaking conditions. Present observations confirm that steady breakers are characterized by the onset of shear flow features, while buoyancy forces related to air entrainment also seem to play a significant role. The interaction of the breaker with the main flow gives rise to a turbulent wake, in which 3-D vorticity structures are visualized by the presence of rising bubbles. Experimental data are discussed in comparison with numerical solutions as well as some results available in the literature.