Numerical Simulations Of Solid-Fluid Coupling With Dilated Polyhedral DEM-SPH Method Based On GPU Parallel Algorithm

In the natural and engineering fields,the coupling interaction between granular materials and fluid media exists widely.In the field of industrial equipment,the fluid-solid coupling analysis of granular materials in industrial equipment is beneficial to the design and optimization of industrial production equipment.In the field of nature,the fluid-solid coupling analysis of granular materials for geological hazards and other problems can avoid the occurrence of safety accidents.In this paper,the dilated polyhedral DEM based on Minkowski Sum method is used to simulate the mechanical behavior of granular materials.The SPH method with weak compressible format is used to simulate the flow field changes of fluids.Compared with sphere element,the dilated polyhedral element based on Minkowski Sum method can more reasonable reflect the geometrical shape of granular materials,such as sediment,rock and ice.SPH method does not need other methods to deal with the free surface of liquid,and is suitable for parallel computing.Particle boundary is usually used in the traditional SPH method for solid wall boundary treatment,which is not conducive to the treatment of complex boundary,but also increases the computational cost.Based on the traditional boundary repulsion force model,a no-particle boundary treatment method is proposed in this paper,The method can reduce the calculation cost and is suitable for the treatment of complex boundary.Based on the above two numerical methods and the simplified boundary repulsion force model,the dilated polyhedron DEM-SPH coupled numerical simulation is realized using interface coupling method,and the velocity correction term and tension correction term are introduced into the SPH method to eliminate non-physical oscillation.The GPU-CUDA parallel computing architecture improves the computing efficiency,increases the computing scale,and makes a comparative analysis of the efficiency with CPU serial program.In order to verify the effectiveness of boundary treatment and coupling method,the numerical simulation of dam break,square cylinder flow and eccentric block water inflow is realized.The simulated results are in good agreement with the existing experimental and numerical results,which shows that the simplified boundary force model proposed in this paper is accurate and effective.On the basis of verifying the rationality and effectiveness of the coupling method in this paper,the DEM-SPH coupling method based on dilated polyhedron is used to simulate and analyze the practical problems of dam-break flow impacting block,submarine pipeline rockfall and wave-absorbing block slope protection respectively,and good numerical results are obtained.In addition,the simulation results of dam-break impact polyhedron are compared with the existing experimental and numerical results,and the results are achieved.