Numerical Simulation Of Dam-break Flow Based On OpenFOAM

At present,China has the largest number of dams in the world.Hydraulic structures such as reservoirs and dams play an important role in flood control,water storage,power generation,irrigation and shipping.However,while dams and reservoirs play social and economic benefits,there are also potential dangers of dam failure.Once dam failure occurs,Dam break flood will cause great damage to the downstream ecological environment and the safety of people’s lives and property.Therefore,it is particularly important to carry out the research on dam break flood routing law.The study of dam break flood can establish and improve an effective flood early warning mechanism,which is of great significance to protect the ecological environment and the safety of people’s lives and property.In this paper,OpenFOAM is used to establish a numerical model to simulate the evolution process of dam break flood and analyze the characteristics of dam break flow movement.Under the conditions of no water in the downstream and different water depth ratio h/H in the upstream and downstream,the dam break flow simulation under 16 working conditions is carried out,and the law of dam break flow movement is explored by analyzing the simulation results of pressure and velocity at the monitoring points.The research contents and results are as follows:(1)The numerical model of dam break flow is constructed based on OpenFOAM user-defined solution method and parameter calibration.The model is verified by typical test cases and simulation results of others.The results show that the simulation results agree well,and the constructed numerical model of dam-break flow can be used to simulate dam break flow.(2)Using the established model,4 working conditions with different upstream water depths are simulated under the condition of no water in the downstream.The results show that the higher the upstream water depth,the greater the dam break flow velocity at the monitoring point,the greater the peak pressure in the simulation,the higher the climbing height on the wall,and the dam break flow is strongly mixed with air in the process of movement,Water energy is mainly consumed rapidly through flow turbulence and mixing with air.(3)Using the established model,12 working conditions with different upstream and downstream water depth ratios are simulated under the condition of downstream water.The results show that when 1/8≤h/H<1/4,the dam break flood velocity is large,the pressure change is obvious,the wall climbing height is large,and the mixing phenomenon of dam break flow and air is obvious.When 1/4≤h/H<3/5,the flow velocity of dam break flow decreases,and the pressure change trend at the monitoring point is more gentle.After the dam break flow evolves downstream for a period of time,negative waves will appear near the dam site,propagate to the upstream reservoir area and disappear gradually.(4)At the initial stage of dam break,the velocity of dam break flood is mainly affected by the upstream and downstream water depth ratio.The smaller the upstream and downstream water depth ratio h/H,the greater the dam break flow velocity;Under the same upstream water depth,the greater the downstream water depth,the smaller the dam break flood velocity.In the process of dam break flood routing,the pressure is affected not only by the upstream water depth,but also by the upstream and downstream water depth ratio;When the upstream water depth is certain,the greater the downstream water depth,the greater the pressure.When the storage capacity is certain,the greater the upstream and downstream water depth ratio h/H,the greater the dam break flow pressure.Figure[71]Table[7]Reference[97]...