Research On Dam Break Simulation And Energy Dissipation Form Based On SPH Method

The simulation of dam break flow is a classic problem in the field of computational fluid dynamics.The traditional simulation based on grid idea will appear grid distortion and low accuracy,especially for the details of the wave roll involved in the process of dam break.However,meshless method does not need to be meshed and has high accuracy.Smoothed particle hydrodynamics(SPH)is one of the fastest developing methods in recent years,which is widely used in fluid simulation(1)Simulation of dam break by sections.The classic dam break is mainly instantaneous break,but the actual dam break is mainly earth rock dam.The development of dam break has a process,showing the characteristics of gradual deepening of dam break.In this paper,the upstream boundary is improved,and the algorithm of upstream breach deepening with time is developed to simulate the progressive breach of earth rock dam,which is more suitable for engineering practice.(2)Simulation of dam break flow impacting plunge pool.Firstly,the evolution process of solitary waves is simulated under the condition of wet riverbed downstream,and the accuracy of the algorithm is verified by comparing with the results in literature.On this basis,a plunge pool is set up in the downstream to simulate the whole process of dam break flow impacting on the plunge pool,to show the evolution of water tongue and the process of crossing over buildings.Combined with the discrete characteristics of particle method,the energy change of dam break flow in the whole process is calculated,and the conversion process of kinetic energy and potential energy is analyzed to calculate the energy dissipation efficiency.(3)Comparison and selection of downstream energy dissipators.Dam break flow will pass through various obstacles in the downstream,such as rocks,houses,forests,etc.,but it is difficult to measure the obstructing effect of these obstacles on dam break flow.In this paper,obstacles are generalized into three shapes of auxiliary energy dissipators,namely triangle,trapezoid and rectangle.The flow pattern changes of dam break flow through these energy dissipators are simulated.The properties of pressure and velocity are analyzed.The energy change curves of three shapes of energy dissipators are obtained by compiling relevant post-processing programs.It provides the basis for the size design of energy dissipater and promotes the application of SPH method in energy dissipation.