Integration of conjugate porous media model into mine ventilation network software

Understanding the behavior, characteristic and interaction of airflow and air/gases leakage through broken rock zones, tunnels and underground mine openings is still a challenging research area due to the complex flow structure through the dynamic nature of underground mine environment. It is crucial to accurately calculate the ventilation parameters when modelling the underground mine ventilation systems. The Atkinson equation along with Kirchhoff laws solved using the Hardy-Cross algorithm has been commonly used in mine ventilation network (MVN) software. However, this model cannot be directly applied for coupled airways with flows through porous media, i.e. air leakage in broken/fragmented rocks, gob of coal mine and caved zone. This paper develops a novel friction factor model that can be easily integrated into typical MVN software to predict the conjugate flow through a broken rock structure. The model is further verified against conjugate 3D computational fluid dynamics model. The results show that the model enables accurate prediction of interaction between flow in underground opening and flow through broken rocks that is extremely useful for practical mine ventilation application.