Numerical Experiment of Methane Distribution in Developing Roadway

The mathematical model for mass transfer between airflow and methane in working face of developing roadway with local ventilation was established based on the study of the airflow pattern and characteristics of the local ventilation. Mesh partition method for local ventilation model was analyzed and the influence of roughness factor of airway surface on simulation results was studied. The boundary conditions to describe the methane emission on roadway surface were analyzed. The Fluent software, a commercial CFD(Computational Fluid Dynamics ) one, was used to simulate the mass transfer process between the airflow and the emitted methane in working face with forced local ventilation by taking RNG k-e two-equation model. The airflow patterns and methane distributions in working face with local ventilation were obtained when methane was emitted from the head of working face at different rates. The study shows that gas emission rate and airflow speed have influence on the airflow field. With the increasing of gas emission rate or the decreasing of airflow speed, the influence of gas emission on airflow field becomes more and more significant.