Modeling of open pit ventilation in ANSYS CFD

The safety and efficiency of open-pit mining operations depend on the design decisions made, including those for ventilation. Calculation of open-pit ventilation should be carried out either using the generally accepted methods, which are briefly described in this article, or using dedicated software. The simplest and fastest calculations for ventilation as compared with the traditional graphical method can be done in the Ansys CFD software package. Based on a series of numerical experiments and their verification, this paper offers recommendations on designing a three-dimensional model and on the grid parameters for modeling open-pit ventilation. Recommendations on the choice of initial and boundary conditions are also given. Three basic approaches are proposed to verify the results obtained. The first approach is to check the invariability of the forward and reverse air flow boundaries when the wind speed changes. The second approach is based on the presence of local recirculation zones on individual benches of the leeward wall in the simulation results. And the third approach is implemented when performing a control calculation of the air velocity at an arbitrary point in the open-pit. Designing the open-pit ventilation is a prerequisite for assessing the hazard level of mining operations. Performing ventilation calculations at the stage when technological solutions are selected helps to select the optimal parameters of the mining system.