Numerical Simulation of the Influence of Working Face Air Leakage on Gob Gas Flow Laws

In order to describe the influence of working face air leakage on gob gas flow laws,a seepage-diffusion model is built and a simulation solution of gob gas flow laws are obtained by using COMSOL Multiphysics numerical simulation software.Simulation results show that,under the impact of air leakage,the gas concentration begins to decrease from the air leak place;gas in the air inlet side moves gradually to the air return side as time goes on,thus a concentration decreasing sector region is formed gradually from air inlet side;gas from the air return side moves to the return airway and makes the gas concentration of the workface corner increase abnormally;the impact of air leakage upon gob gas movement is limited,the gob near the air return side has a rather high gas concentration and makes it a gas enrichment region.