Experimental study of the flow field with spilling type breaking

This paper shows the results of an experimental work on the spilling type breaking flow field produced by a hydrofoil positioned in a uniform current. From the examination of the Laser Doppler Anemometer results downstream of the hydrofoil a flow field similar to a mixing layer, close to the breaking zone, and a flow field similar to a wake were found. The conclusions that can be drawn by the studies conducted can be summarized as follows: (i) downstream of the hydrofoil it is possible to distinguish two regions of flow, namely one immediately downstream of the hydrofoil, including spilling characterized by a mixing of water and air, and one downstream of the same spilling; (ii) in first of the aforementioned regions the flow is similar to that of a mixing layer, while, in the downstream region, it shows conditions similar to a wake; (iii) the experiments furnish information on the turbulence characteristics in the two regions, and extract the zone where the wake effect can be considered negligible; (iv) the time-averaged free surface height presents a decreasing trend from the wake origin