GPU-accelerated Numerical Simulation Of Dam Failure Flow By SPH Method

The simulation and visualisation of dam-break flows is an important issue in the field of simulation in water resources engineering,and the accurate simulation of the flow characteristics of dam-break flows is important for the design and safety assessment of water resources projects.The study of dam-break flows involves strong non-linearities of the fluid and various complex physical problems,for which direct analytical solutions are not possible.However,with the advent of various approximate solutions,especially numerical simulation methods,good approximate solutions for dam-break flows can be obtained by numerical solution using computer technology,which can provide a viable technical tool for the study of such hydraulic engineering problems and is worthy of further study.The traditional grid simulation method is perplexed by the constraint of water continuity condition and the interface tracking problem of free liquid surface,so it is inherently difficult to solve the fluid problem.As a meshless method emerging in modern times,SPH method uses particle flow to simulate free surface flow,which eliminates the natural disadvantages of grid method and completely avoids the problem of grid generation and distortion.When the SPH method uses a large number of particles for calculation,it is often necessary to consider the computational efficiency,especially in the high-dimensional flow simulation problem,it is necessary to focus on how to improve the calculation speed of the SPH method in order to obtain effective numerical results in a reasonable time range.This paper is based on the SPH approach to GPU-accelerated optimization of computation with the help of CUDA parallel mode,and focuses on the following research work:(1)The main contents are as follows:(1)the basic theory of SPH method.Firstly,the basic idea of SPH method,kernel approximation,particle approximation and numerical techniques used in SPH method are introduced,and the boundary treatment methods of solid wall boundary conditions and free boundary conditions are introduced,with emphasis on the boundary repulsion method and mirror image virtual particle method involved in dynamic boundary conditions and the dynamic boundary method involved in moving boundary conditions.(2)Theoretical research on GPU acceleration and CUDA parallel computing.Under the CUDA architecture calculation accelerated by GPU,combined with a two-dimensional numerical example,Poiseuille flow is simulated and verified,and the error between the calculated results and the numerical solution is less than 4%.(3)Study on two-dimensional flow simulation of dam break.Comparing the SPH simulation results with the literature experimental results,it is found that the calculated results of the SPH method are in agreement with the literature experimental results of 88.4%.The convergence and divergence are explored from the point of view of different smooth length and particle number,and the proportional coefficient converges to 1.25 and the particle number converges to 44034.(4)Numerical simulation of three-dimensional dam-break flow.The velocity and flow pattern of the burst flow,the force of the energy dissipation obstacle and each measuring point and the energy change of the water body are analyzed;the kinetic energy change of the water body is calculated quantitatively,and the energy dissipation effect of the trapezoidal obstacle block is the best,and the energy dissipation efficiency is 14.154%.