Simulation Study To Flow Characteristics Of Chain Dam Break

Nowdays there are the most dams in China throughout the world. Reservoirs play important roles in flood control, water supply, hydropower generation, irrigation, etc. Meanwhile, in order to fully rational use of water resources, many basin in southwest China carried out the construction of Cascade Reservoirs. However, there were many various constraints when the dams were built, caused a lot of reservoirs and constructions were of poor quality. At the same time because of lacking in regular maintenance, many reservoirs inevitably appeared the phenomenon of aging and dam breakage. And the effects of unpredictable external factors, such as the sudden earthquake, flood, landslides and war, etc, may lead to the occurrence of dam break accident. Through the research on the issue of dam break can be found that many scholars d d a lot of research for the dam-break issue and achieved fruitful results.Unfortunately, most studies just discuss single dam break problem. The research on characteristics of chain dam break flow is still very rare for cascade reservoirs group.Based on some experimental researches of predecessors and knowledge of hydraulics and water dynamics, a numerical model of dam break flow was established in this paper. The dam break flow was simulated for single stage reservoir dam break and two-stages chain reservoir dam break. Then through the results of the numerical study, the effects of upstream and downstream water depth in front of the reservoir, river bottom slope and dam spacing of chain reservoir were studied. This paper main research work and innovation points are as follow.(1) The basic theories of fluid motion were analysed. And then based on these theories, a numerical model of dam break flow was established and the applicability of the model was verified using the experimental data.(2) The single stage reservoir dam break flow was simulated by the COBRAS model in this paper. The results show that the differences in the process of the single stage dam break flow stream and disturbance in the downstream reservoir are obviously under the conditions of different water depth ratio in the upstream and downstream reservoirs and river bottom slopes.(3) The two-stages reservoir dam break flow was simulated by the COBRAS model in this paper. The results indicated the different process of dam break flow stream and disturbance in a downstream reservoir on the various conditions of water depth ratio in the upstream and downstream reservoirs, river bottom slopes and dam spacing.(4) Under the same conditions, the change of water level in the downstream reservoir caused by single stage and two-stages chain dam break flow was simulated. The results indicated the difference of dam break flow characteristic between single-stage dam break flow and two-stages chain dam break flow because of the duplicate effect by two-stages chain dam break...