Numerical Study of the Water Surface Movement During a Dam Break on a Slope with Cascade Dike from Sediment

A dam break in a real area with underlying cascading reservoirs is an extremely dangerous disaster. In this work, a numerical simulation of the flow during the dam break of the reservoir in a cascade sequence with subsequent sediment transport was carried out. To validate the mathematical model and the numerical algorithm, two test problems were performed, the first one was the evolution of complex dam break flows on an inclined surface, and the second problem was a dam break taking into account sediments. The obtained numerical results were compared with experimental data and numerical results of other authors. To take into account the evolution of sediments, an incompressible flow was considered, which includes three phases: water, air, and sediment phases. To describe this process, a modified model was used that takes into account the Newtonian model for describing the movement of liquid and air, and a non-Newtonian model was used to describe the movement of sediment. To reduce the peak pressure on the dam walls, an embankment dam was used, located between the dams, which reduces the peak pressure on the lower wall of the dam. From the obtained data, it can be seen that the various properties of the embankment dam have a very strong influence on the obtained solutions, both in terms of the pressure distribution on the walls of the dam and changes in the water level. At the same time, it should be noted that there is an effect of a strong oscillatory change in the water surface, which can negatively affect the downstream dams. And also, with certain properties of the deposit, one can notice almost 1.8 times decrease in pressure on the wall of the underlying dam. The results of this work can be valuable in the field of water resources and hydropower to prevent dam break of a cascade group of reservoirs. Thus, this study focuses on the flooding process during the dam break of a cascade dam.