Coupling simulation model between mine ventilation network and gob flow field

Many numerical simulation studies of coal spontaneous combustion have focused on the leakage flow field in the mine gob. However, most of these studies isolate the gob from the mine ventilation system, failing to consider the effects of air leakage on gob boundary conditions. A novel model coupling the mine ventilation network (MVN) and gob flow field (GFF) has been developed to simulate the overall mine ventilation system. The concept of network boundary node was proposed and the corresponding air flow rate balance equations were developed based on the node pressure method for MVN calculation and the finite element method for GFF simulation. These equations, containing the rate of air flow not only from the branches but also from the gob, revealed the coupling relationship between 1D MVN and 2D/3D OFF. An iterative solution technique was developed to solve the coupling model, which has been incorporated into a program i-MVS. An illustrative example with coarse mesh is used to verify the stability and convergence of the model. Results of an application case show that the coupling model has sufficient precision and the developed software is efficient in implementing the computations.