SPH numerical simulation of non-steady sand ripple wind-sand flow structure.

The Smoothed Particle Hydrodynamics (SPH) method is used to numerically simulate the unsteady sand ripple wind-sand flow movement in a small scale. Compared with the traditional grid-based numerical method, the SPH method uses discrete independent particles to represent the solution domain, get rid of the constraints of the computational grid, and completely solve various problems caused by large deformation or distortion of the grid based on the Euler grid method. Because it also includes the Lagrangian dynamics method, it can easily track the trajectory of any single particle, so the SPH method has unique advantages when dealing with the two-phase flow coupling of wind and sand. This paper expounds the theoretical basis and calculation method of SPH method and focuses on the design idea of applying the core factors in the SPH formula to the numerical simulation program. By discretizing the SPH numerical model of the sand ripple wind-sand two-phase flow, the temporal and spatial changes of the sand particle group on the slope surface during the wind-sand movement are simulated. The formation and development process of macro-wind-sand flow and the saltation law of micro-typical particles are analyzed, which are consistent with the existing wind tunnel experiment results, and the accuracy of SPH numerical simulation method is verified. The results show that the calculation accuracy of this method is high, and it provides a scientific theoretical basis for our further research and prevention of sand damage.