A Mixed Finite Element solver for liquid-solid and liquid-liquid impacts

摘要

The impact of a dam-break surge on a wall has been numerically modeled in this work. The incompressible and inviscid surge is advancing over a dry bed and the air entrapment has not been considered in the equations describing the phenomenon. The global quantities of interest has been evaluated in the framework of the potential theory. The numerical method couples a potential flow solver with an ordinary differential equation (ODE) solver. The potential flow solver is an implementation of a Mixed Finite Element method (MFE). A second order Crank-Nicholson scheme is used as ODE solver. The MFE solver turns out to be second order accurate for both the potential and the flow field and this is the main advantage as compared to the corresponding finite volume scheme. The method has been used for the calculation of the 2-D unsteady, incompressible, free surface impact of clear water bores on vertical plane walls. Due to the accuracy of the scheme, a good agreement with the experimental data is obtained. A liquid-liquid impact has also been attempted.