SPH numerical simulation study on wind-sand flow structure of multi-diameter sand

Smoothed particle hydrodynamics (SPH) method is used to numerically simulate the wind-sand flow movement of multi-diameter sand. The main feature of this method is meshless discretization of computational domain. The problem domain is represented by a series of particles with their own physical properties and arbitrary distribution. Particles produced by this method can be endowed with the natural properties of sand and air in wind-sand flow. By solving each particle, a more accurate numerical solution can be obtained, so the application of SPH in the microscopic study of wind-sand flow can accurately track the trajectory of a single sand particle, which is also the advantage of SPH in the study of wind-sand flow. This paper expounds the theoretical basis and specific methods of SPH method for multi-diameter sand and optimizes the wind-sand flow model, so that the multi-diameter sand is more in line with the natural accumulation state of the sand bed, and the simulation results of the wind-sand flow model are more accurate and rigorous. Through the SPH numerical simulation of the wind-sand flow structure of multi-diameter sand, the simulation results are studied macroscopically and microscopically. Compared with the previous research results, the validity of the SPH method in the numerical simulation of wind-sand flow of multi-diameter sand is verified. By comparing the simulation results of the wind-sand flow of multi-diameter sand and single-diameter sand, it is confirmed that the simulation results considering sand with multi-diameter distributions are more accurate than those with single-diameter in the wind-sand flow.