Three-dimensional nonhydrostatic numerical simulation for the PBL of an open-pit mine

A high-resolution, nonhydrostatic, three-dimensional planetary boundary-layer (PBL) model was established considering the characteristic features of an open-pit mine, which is only (2 km x 2 km) wide and more than 100 m deep. The (E - ε) closure scheme was used in the model. Physical processes such as shortwave radiation of the sun and its uneven distribution on the ground, longwave radiation of earth-atmosphere systems, sensible and latent heat fluxes and heat flowing into the substrate of the earth, were involved in the model. Using this model PBL structures over this kind of microscale concave terrain (an open-pit mine) were fully studied and numerical experiments on the effects of parameters including H, depth of the mine, α, slope angle of the mine, u, incident airflow velocity, and P, indicating shear of the initial velocity profile, on the PBL were also made. Finally, the evolution process of the PBL was simulated. The results showed that a characteristic and major feature of the PBL is re-circulation, which is greatly influenced by the topography of the mine and the meteorolgical conditions therein. Thermal and mechanical forcing play different but important roles in the evolution of the PBL.