Research on the Influencing Factors and Prediction Model of Impact Airflow in the Process of Unloading of an Ore Pass Based on a Coupled Computational Fluid Dynamics and Discrete Element Method

[Image: see text] In this paper, a coupled computational fluid dynamics and discrete element method (CFD-DEM) is used to numerically simulate the energy transfer of the ore falling process and the change law of impact airflow velocity under different influencing factors. The results are as follows: the total drag force is an important factor that determines the impact airflow velocity. The greater the total drag force, the greater the impact airflow velocity. The impact airflow velocity increases with the increase of mass flow rate and discharge height and decreases with the increase of ore size, and it is found that the discharge height has the greatest impact on the impact airflow velocity, the ore size is the second, and the mass flow rate is the smallest. Therefore, in the allowable range of mine production, the discharge height should be appropriately reduced. The mathematical model of the impact airflow velocity is obtained by multivariate nonlinear regression on the experimental results of orthogonal experiments.