ACCURATE DESCRIPTION OF THE JET FLOW DEVELOPING DURING WATER IMPACT

The jet flow originated during the water impact of rigid bodies is investigated. In the framework of a potential flow assumption, a numerical model is developed which allows an efficient and accurate description of the unsteady flow taking place within the thin jet layer. To this aim, the modeled part of the jet is discretized with small control volumes and, inside each one, the velocity potential is approximated by local harmonic expansions, coefficients of which are recovered by enforcing boundary conditions on the body and on the free surface. An additional matching condition between contiguous volumes is also applied to achieve regularity. The model is incorporated within a boundary element solver, which is used to determine the solution in the remaining part of the fluid domain. For validation, the model is used to simulate the flow generated by the wedge impact with constant entry velocity. A rather good agreement with the similarity solution is achieved both in terms of free surface shape and pressure distribution.