Numerical Simulation of Flow Field and Gas Transportation in Goaf of Fully Mechanized Sub-Level Caving Face with J-Shape Ventilation System

Aimed at the new J-shape ventilation system of fully mechanized sub-level caving face,the model of computational fluid dynamics was set up for simulating the flow field of the goaf under J-shape ventilation system.Through numerical simulation,the characteristics of goaf flow field and gas transportation under J-shape and U-shape ventilation systems were analyzed.Under different conditions of goaf size,discharge capacity of the special return and location of the discharge fans,the patterns of goaf flow field and gas transportation under J-shape ventilation system were analyzed systemically.The results show that the concentrated air leakage from the goaf to the upper corner can be eliminated by applying J-shape ventilation system,and the problem of gas accumulation at the upper corner under U-shape ventialtion system can be effectively solved.