Mechanical properties of saltating soil particles insteady-state wind field

Acted force on saltating soil particles is a key problem to study micro-mechanism in wind erosion disaster. In this paper, steady-state two phase flow model is suggested with the coupling interaction between air and particles, and the different force acted on saltating soil particles is theoretically calculated and analyzed. The numerical results show that ratio of the drag force to gravitation is between 2 and 20, but the ratio of Magnus force, Saffman force and electrostatic force to gravitation are only between 0 and 0.5. In the same wind field, and with the same lifting-off velocity, from the ratio of the different force to gravitation and the effect of the different force for saltating soil particles trajectories, it can be seen that the drag force and gravitation play dominant roles in soil particles movement, the effect of Magnus and electrostatic force are smaller, and Saffman force is the smallest and can be neglected. The soil particle motion trajectories show that the simulation results of this model is agreement to the experimental results. Acted by different force, the difference of soil particles trajectories is obvious, but acted by gravity, drag force and Magnus force, soil particles trajectories has minimum error, which fully shows that the model is reasonable. The study can provide a theoretical basis for farmland protection measures.