Experimental and Numerical Study of Sediment Scour Under Impinging Vertical Jet

Local scour by a submerged jet is a typical phenomenon of water-soil interaction, present in many engineering situations such as gates, sewers, spillways, pipes, dredging of channels and ports. Its complexity causes that the problem is still scientifically open and numerical simulation is an effective tool to help to understand the different physical processes involved. The present work focuses on the development of physical and numerical modeling of the sediment scour under impinging vertical submerged jet, in order to maximize the main strengths of both complementary approaches. The base CFD used, caffa3d.MBRi, is an open-source finite volume code in block structured curvilinear meshes for an incompressible viscous fluid. Fluid-particle systems are modeled as pseudo-continuous materials of a single phase and the presence of particles is taken into account in terms of an effective viscosity. A set of numerical simulations were performed to represent local scour hole by changing the main hydro-sediment parameters. Eighteen physical experiments were carried out in the laboratory of IMFIA in order to validate the numerical model. The simulation results show that the development of the scour hole and the different flow patterns are in good agreement with the present experiments and also previously published results. Some of the differences found can be partially explained by the characteristics of the sediment; particularly sediment granulometry and internal friction angle of the material are aspects that must be studied further.