Numerical study of the wave impacts generated in a wet dam break

Abstract

This paper focuses on the numerical analysis of the different wave impacts generated in a wet dam break by varying the downstream depth and the position of the obstacle. With this relatively simple set-up, five hundred impacts were simulated, providing a comprehensive dataset covering the four classical impact types : sloshing, flip-through, aerated and broken wave impacts. We determined the dam break parameters for which the flip-trough impacts occur and showed that among all the flip-through impacts, there is one optimum generating a pressure peak larger that the others. Compared to impact pressures recorded or simulated with a dam break flow in most previous studies, the present numerical work reached values one order of magnitude larger. Therefore with a dam break on wet bottom, it seems possible to generate strong wave impacts in a short duration. This has to be verified experimentally specifically focusing on the measurements repeatability due to the obvious effect of the gate dynamics effect on the subsequent flow. When and if confirmed, this simple set-up could be used to validate numerical models without the need of a long propagation stage before impact.