Experimental study of the scour regimes downstream of an apron for intermediate tailwater depths

Local scour, Non-cohesive bed, Protection apron, Submerged jet, Open channel flow, LDA mesurements, ADV measurements, Visualization.

Local scour due to 2-D submerged horizontal jets is a well-known topic of hydraulic research. When the jet is directly injected on the erodible bed and the tailwater depth is either “deep” or “shallow”, the equilibrium state characteristics of the scoured bed profile are mainly a function of the densimetric Froude number. If the submergence is between these two extremes, for fixed Froude number, three different scour re-gimes are possible, depending on the jet mainstream position. This paper integrates previous work by the Au-thors concerning the experimental description of the three mentioned regimes, in presence of a protection apron. The results of the investigation are also intended as a dataset to validate numerical models able to simulate the interaction between free-surface flows and non-cohesive granular beds.